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SMD marking

15

Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables.

14 parts are printed 15

Not sure which one you have?

Answer up to 4 quick questions and these 14 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • DTA124EE3SOT-416Digital transistor (PNP, resistors built in), 3 pins, ROHM
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    ROHM
    Package
    SOT-416
    Pins
    3
    Details
    PNP digital transistor (bias resistor built-in); R1 = 22kOhm, R2 = 22kOhm
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor DTA124EE3, opens in a new tab
  • DTA124EEBSOT-416Digital transistor (PNP, resistors built in), 3 pins, ROHM
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    ROHM
    Package
    SOT-416
    Pins
    3
    Details
    PNP digital transistor (bias resistor built-in); R1 = 22kOhm, R2 = 22kOhm
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor DTA124EEB, opens in a new tab
  • DTA124EKASOT-23Digital transistor (PNP, resistors built in), 3 pins, ROHM
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    ROHM
    Package
    SOT-23
    Pins
    3
    Details
    PNP digital transistor (bias resistor built-in); R1 = 22kOhm, R2 = 22kOhm
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor DTA124EKA, opens in a new tab
  • DTA124EMSOT-723Digital transistor (PNP, resistors built in), 3 pins, JSCJ
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    JSCJ
    Package
    SOT-723
    Pins
    3
    Details
    Digital transistor (bias resistors built in), PNP
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor DTA124EM, opens in a new tab
  • DTA124EU3SOT-323Digital transistor (PNP, resistors built in), 3 pins, ROHM
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    ROHM
    Package
    SOT-323
    Pins
    3
    Details
    PNP digital transistor (bias resistor built-in); R1 = 22kOhm, R2 = 22kOhm
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor DTA124EU3, opens in a new tab
  • DTA124EUBSOT-323Digital transistor (PNP, resistors built in), 3 pins, ROHM
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    ROHM
    Package
    SOT-323
    Pins
    3
    Details
    PNP digital transistor (bias resistor built-in); R1 = 22kOhm, R2 = 22kOhm
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor DTA124EUB, opens in a new tab
  • ESD5Z15SOD-523ESD protection diode, 2 pins, Diotec
    What it is
    ESD protection diode
    Maker
    Diotec
    Package
    SOD-523
    Pins
    2
    Details
    ESD Protection Diodes in SMD
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor ESD5Z15, opens in a new tab
  • PDTA113ETSOT-23Digital transistor (PNP, resistors built in), 3 pins, Nexperia
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Nexperia
    Package
    SOT-23
    Pins
    3
    Details
    50 V, 100 mA PNP resistor-equipped transistor; R1 = 1 kΩ, R2 = 1 kΩ
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PDTA113ET, opens in a new tab
  • PDTC115EUSOT-323Digital transistor (NPN, resistors built in), 3 pins, Nexperia
    What it is
    Digital transistor (NPN, resistors built in)
    Maker
    Nexperia
    Package
    SOT-323
    Pins
    3
    Details
    50 V, 20 mA NPN resistor-equipped transistor; R1 = 100 kΩ, R2 = 100 kΩ
    Source
    From the manufacturer's datasheet

    Is it dead?

    Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

    Working, it reads

    Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

    Dead, it reads

    • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
    • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
    • Base to emitter near 0 Ω: failed short.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
    Watch for:
    On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PDTC115EU, opens in a new tab
  • SML4744SMAZener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SMA
    Pins
    2
    Details
    15 V Zener diode
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor SML4744, opens in a new tab
  • EIA-96:150603Precision resistor (EIA-96 code), 2 pins
    What it is
    Precision resistor (EIA-96 code)
    Maker
    Not recorded
    Package
    0603
    Pins
    2
    Details
    EIA-96 precision chip resistor, significand 14; the printed mark adds a multiplier letter (15A = 140 Ohm, 15B = 1.4 kOhm)
    Source
    Added by hand from a published table

    Is it dead?

    Ohms range, across it, power off.

    Working, it reads

    Its marked value, within tolerance. On the board it reads the same or lower, because everything around it sits in parallel.

    Dead, it reads

    • Open: burnt, cracked, or eaten through by sulphur. The commonest failure.
    • Well above its marked value: drifted high.
    • On the board, clearly higher than its marked value: it has failed, since the board can only pull a reading down.
    On the board:
    A reading lower than marked on the board proves nothing; lift one end. A reading higher than marked is a fault even on the board.
    Compare:
    The same position on another channel usually carries the same value, and so does the matching part on another board.
    Watch for:
    A burnt resistor usually means the part it feeds pulled too much. Find that before fitting a new one, or it burns too. The marking, not the reading, says what to fit.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor EIA-96:15, opens in a new tab
  • 3 more parts have no package on record
    • BAS125-05WSwitching diode, Infineon
      What it is
      Switching diode
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted or one leg off the pad. Red probe on the anode.

      Working, it reads

      About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • Open both ways: failed open.
      • A reading the wrong way round as well: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor BAS125-05W, opens in a new tab
    • ESDUNF15VB1ESD protection diode, JSCJ
      What it is
      ESD protection diode
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      ESD protection diode, VRWM 15 V
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, from the protected line to ground, part lifted if you can.

      Working, it reads

      A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

      Dead, it reads

      • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
      • A reading both ways on a one-way part: leaky.
      • A one-way part open both ways: failed open.
      On the board:
      On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
      Compare:
      The same part on the next line or connector pin is the healthy reading to compare with.
      Watch for:
      A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor ESDUNF15VB1, opens in a new tab
    • VCUT15G1-SD0ESD protection diode, Vishay
      What it is
      ESD protection diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Bidirectional Symmetrical (BiSy) Single Line ESD-Protection Diode in Silicon Package
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, from the protected line to ground, part lifted if you can.

      Working, it reads

      A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

      Dead, it reads

      • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
      • A reading both ways on a one-way part: leaky.
      • A one-way part open both ways: failed open.
      On the board:
      On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
      Compare:
      The same part on the next line or connector pin is the healthy reading to compare with.
      Watch for:
      A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor VCUT15G1-SD0, opens in a new tab
9 more parts are printed with a code easy to misread as 15

Printed with a code easy to misread

One character differs, and it is one that is easy to confuse under a lamp. The odd one out is marked on each.

  • AO3495printed L5SOT-23P-channel MOSFET, 3 pins, Alpha & Omega Semiconductor

    Printed L5 on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

    What it is
    P-channel MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    SOT-23
    Pins
    3
    Details
    P-channel MOSFET (8-60 V)
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
    • No body diode at all: failed open.
    On the board:
    On the board the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AO3495, opens in a new tab
  • AOSS32334Cprinted LSSOT-23MOSFET, 3 pins, Alpha & Omega Semiconductor

    Printed LS on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

    What it is
    MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    SOT-23
    Pins
    3
    Details
    Low-voltage (12-30 V) MOSFET
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted.
    • No body diode at all: failed open.
    On the board:
    On the board the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOSS32334C, opens in a new tab
  • BZD17C5V6Pprinted I5SOD-123FZener diode, 2 pins, Vishay

    Printed I5 on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-123F
    Pins
    2
    Details
    5.6 V Zener diode
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BZD17C5V6P, opens in a new tab
  • BZD17C100Pprinted L5SOD-123FZener diode, 2 pins, Vishay

    Printed L5 on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-123F
    Pins
    2
    Details
    100 V Zener diode
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BZD17C100P, opens in a new tab
  • BZX384-B8V2printed L5SOD-323Zener diode, 2 pins, Nexperia

    Printed L5 on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BZX384-B8V2, opens in a new tab
  • PMEG2005EBprinted L5SOD-523Schottky diode, 2 pins, Nexperia

    Printed L5 on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

    What it is
    Schottky diode
    Maker
    Nexperia
    Package
    SOD-523
    Pins
    2
    Details
    20 V, 500 mA low VF Schottky barrier diode
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • A reading the wrong way round as well: leaky.
    • Open both ways: failed open.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PMEG2005EB, opens in a new tab
  • 3 more parts have no package on record
    • BCR405Uprinted L5Digital transistor (resistors built in), Infineon

      Printed L5 on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

      What it is
      Digital transistor (resistors built in)
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead?

      Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

      Working, it reads

      Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

      Dead, it reads

      • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
      • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
      • Base to emitter near 0 Ω: failed short.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
      Watch for:
      On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor BCR405U, opens in a new tab
    • BF770Aprinted LSRF transistor, Infineon

      Printed LS on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

      What it is
      RF transistor
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted or its base leg off the pad.

      Working, it reads

      From the base, one probe colour reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.

      Dead, it reads

      • Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
      • The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
      • Only one junction reads, or none: a junction has failed open. It then looks like a diode.
      • A reading the wrong way round, where it should be open: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor BF770A, opens in a new tab
    • TLV803ED17DPWprinted ISVoltage supervisor, 5 pins, Texas Instruments

      Printed IS on the part. Easy to misread as 15. Check that character with a loupe before you order anything.

      What it is
      Voltage supervisor
      Maker
      Texas Instruments
      Package
      Not recorded
      Pins
      5
      Details
      Low Power 250-nA IQ and Small Size Supply Voltage Supervisors
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage with the board powered; ohms from each pin to ground with it off.

      Working, it reads

      Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

      Dead, it reads

      • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
      • Supply present, output stuck: failed, or its load has.
      On the board:
      A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
      Compare:
      The surest reference is the same IC on a working board, measured pin by pin.
      Watch for:
      Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor TLV803ED17DPW, opens in a new tab
27 more parts have codes that begin with 15

Codes that begin with 15

For a marking with its end worn or burnt off. Each one shows its full printed code.

  • 1.5SMC15Aprinted 15ASMCTVS diode, 2 pins, Vishay

    Printed 15A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    TVS diode
    Maker
    Vishay
    Package
    SMC
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor 1.5SMC15A, opens in a new tab
  • 1.5SMC15CAprinted 15CSMCTVS diode, 2 pins, Vishay

    Printed 15C. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    TVS diode
    Maker
    Vishay
    Package
    SMC
    Pins
    2
    Details
    1500 W TVS diode, bidirectional
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor 1.5SMC15CA, opens in a new tab
  • 1.5SMC150Aprinted 150ASMCTVS diode, 2 pins, Vishay

    Printed 150A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    TVS diode
    Maker
    Vishay
    Package
    SMC
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor 1.5SMC150A, opens in a new tab
  • 1.5SMC150CAprinted 150CSMCTVS diode, 2 pins, Vishay

    Printed 150C. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    TVS diode
    Maker
    Vishay
    Package
    SMC
    Pins
    2
    Details
    1500 W TVS diode, bidirectional
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor 1.5SMC150CA, opens in a new tab
  • 1SMA150Zprinted 150ASMAZener diode, 2 pins, Taiwan Semiconductor

    Printed 150A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Zener diode
    Maker
    Taiwan Semiconductor
    Package
    SMA
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor 1SMA150Z, opens in a new tab
  • 1SMA150ZHprinted 150ASMAZener diode, 2 pins, Taiwan Semiconductor

    Printed 150A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Zener diode
    Maker
    Taiwan Semiconductor
    Package
    SMA
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor 1SMA150ZH, opens in a new tab
  • BZT52B15printed 15VBSOD-123FZener diode, 2 pins, Taiwan Semiconductor

    Printed 15VB. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Zener diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-123F
    Pins
    2
    Details
    SMD Planar Zener Diodes
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BZT52B15, opens in a new tab
  • BZT52C15printed 15VZSOD-123FZener diode, 2 pins, Taiwan Semiconductor

    Printed 15VZ. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Zener diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-123F
    Pins
    2
    Details
    SMD Planar Zener Diodes
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BZT52C15, opens in a new tab
  • PJSD15Wprinted 15WSOD-323ESD protection diode, 2 pins, Panjit

    Printed 15W. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    ESD protection diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PJSD15W, opens in a new tab
  • PJSD15W-AUprinted 15WSOD-323ESD protection diode, 2 pins, Panjit

    Printed 15W. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    ESD protection diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board:
    On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PJSD15W-AU, opens in a new tab
  • S15DLWprinted 15DLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15DLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15DLW, opens in a new tab
  • S15DLWHprinted 15DLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15DLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15DLWH, opens in a new tab
  • S15GLWprinted 15GLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15GLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15GLW, opens in a new tab
  • S15GLWHprinted 15GLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15GLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15GLWH, opens in a new tab
  • S15JLWprinted 15JLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15JLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15JLW, opens in a new tab
  • S15JLWHprinted 15JLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15JLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15JLWH, opens in a new tab
  • S15KLWprinted 15KLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15KLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15KLW, opens in a new tab
  • S15KLWHprinted 15KLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15KLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15KLWH, opens in a new tab
  • S15MLWprinted 15MLWSOD-123WRectifier, 2 pins, Taiwan Semiconductor

    Printed 15MLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Rectifier
    Maker
    Taiwan Semiconductor
    Package
    SOD-123W
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board:
    On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor S15MLW, opens in a new tab
  • 8 more parts have no package on record
    • 1SMB3EZ15printed 15BZener diode, Panjit

      Printed 15B. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Zener diode
      Maker
      Panjit
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

      Working, it reads

      About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • Open both ways, forward too: failed open.
      • Holds well off its rated voltage on the supply test: drifted.
      • A soft knee, or a voltage that creeps on the supply test: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor 1SMB3EZ15, opens in a new tab
    • 1SMB3EZ15-AUprinted 15BZener diode, Panjit

      Printed 15B. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Zener diode
      Maker
      Panjit
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

      Working, it reads

      About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • Open both ways, forward too: failed open.
      • Holds well off its rated voltage on the supply test: drifted.
      • A soft knee, or a voltage that creeps on the supply test: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor 1SMB3EZ15-AU, opens in a new tab
    • ESDH15VP1printed 15HESD protection diode, JSCJ

      Printed 15H. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      ESD protection diode
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      ESD protection diode, VRWM 15 V
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, from the protected line to ground, part lifted if you can.

      Working, it reads

      A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

      Dead, it reads

      • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
      • A reading both ways on a one-way part: leaky.
      • A one-way part open both ways: failed open.
      On the board:
      On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
      Compare:
      The same part on the next line or connector pin is the healthy reading to compare with.
      Watch for:
      A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor ESDH15VP1, opens in a new tab
    • ESDQ15VFD1printed 15PESD protection diode, JSCJ

      Printed 15P. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      ESD protection diode
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      ESD protection diode, VRWM 15 V
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, from the protected line to ground, part lifted if you can.

      Working, it reads

      A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

      Dead, it reads

      • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
      • A reading both ways on a one-way part: leaky.
      • A one-way part open both ways: failed open.
      On the board:
      On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
      Compare:
      The same part on the next line or connector pin is the healthy reading to compare with.
      Watch for:
      A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor ESDQ15VFD1, opens in a new tab
    • ESDUEL15VB1printed 15DESD protection diode, JSCJ

      Printed 15D. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      ESD protection diode
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      ESD protection diode, VRWM 15 V
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, from the protected line to ground, part lifted if you can.

      Working, it reads

      A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

      Dead, it reads

      • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
      • A reading both ways on a one-way part: leaky.
      • A one-way part open both ways: failed open.
      On the board:
      On the board, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
      Compare:
      The same part on the next line or connector pin is the healthy reading to compare with.
      Watch for:
      A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor ESDUEL15VB1, opens in a new tab
    • PLZ15Aprinted 15AZener diode, Vishay

      Printed 15A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Zener diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      15 V Zener diode
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

      Working, it reads

      About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • Open both ways, forward too: failed open.
      • Holds well off its rated voltage on the supply test: drifted.
      • A soft knee, or a voltage that creeps on the supply test: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor PLZ15A, opens in a new tab
    • PLZ15Bprinted 15BZener diode, Vishay

      Printed 15B. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Zener diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      15 V Zener diode
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

      Working, it reads

      About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • Open both ways, forward too: failed open.
      • Holds well off its rated voltage on the supply test: drifted.
      • A soft knee, or a voltage that creeps on the supply test: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor PLZ15B, opens in a new tab
    • PLZ15Cprinted 15CZener diode, Vishay

      Printed 15C. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Zener diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      15 V Zener diode
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

      Working, it reads

      About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • Open both ways, forward too: failed open.
      • Holds well off its rated voltage on the supply test: drifted.
      • A soft knee, or a voltage that creeps on the supply test: leaky.
      On the board:
      On the board this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor PLZ15C, opens in a new tab

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