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SMD marking

88

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.

2 parts are printed 88

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • EIA-96:880603Precision 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 80.6; the printed mark adds a multiplier letter (88A = 806 Ohm, 88B = 8.06 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-96:88, opens in a new tab
  • 1 more part has no package on record
    • BBY58-02LInfineon
      What it is
      Not recorded
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range and ohms range, part lifted.

      Working, it reads

      Depends on what it is. The datasheet, or an identical part, says.

      Dead, it reads

      • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
      • Open between every pair of pins: failed open, or a part that reads open when working.
      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.

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

      Datasheetfor BBY58-02L, opens in a new tab
25 more parts are printed with a code easy to misread as 88

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.

  • BC817-25printed 8BSOT-23NPN transistor, 3 pins, Panjit

    Printed 8B on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    NPN transistor
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    Details
    45 V, 500 mA NPN small-signal transistor, gain group 25
    Source
    From the manufacturer's datasheet

    Is it dead?

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

    Working, it reads

    Red probe on the base 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 BC817-25, opens in a new tab
  • BC817-25-AUprinted 8BSOT-23Transistor, 3 pins, Panjit

    Printed 8B on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Transistor
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    Details
    Bipolar transistor
    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 BC817-25-AU, opens in a new tab
  • BZT52H-C3V9printed B8SOD-123FZener diode, 2 pins, Nexperia

    Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-123F
    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 BZT52H-C3V9, opens in a new tab
  • BZT52H-C5V1printed BBSOD-123FZener diode, 2 pins, Nexperia

    Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-123F
    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 BZT52H-C5V1, opens in a new tab
  • BZX84-C56printed B8SOT-23Zener diode, 3 pins, Nexperia

    Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOT-23
    Pins
    3
    Details
    56 V approx. ±5% voltage regulator (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 BZX84-C56, opens in a new tab
  • BZX384B4V3printed B8SOD-323Zener diode, 2 pins, Vishay

    Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-323
    Pins
    2
    Details
    4.3 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 BZX384B4V3, opens in a new tab
  • BZX384B62printed 8BSOD-323Zener diode, 2 pins, Vishay

    Printed 8B on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-323
    Pins
    2
    Details
    62 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 BZX384B62, opens in a new tab
  • MM3Z10Bprinted 8BSOD-323Zener diode, 2 pins, Diotec

    Printed 8B on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Diotec
    Package
    SOD-323
    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 MM3Z10B, opens in a new tab
  • MMDT5211Wprinted B8SOT-323Digital transistor (resistors built in), 3 pins, Diotec

    Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Digital transistor (resistors built in)
    Maker
    Diotec
    Package
    SOT-323
    Pins
    3
    Details
    SMD Digital NPN Transistors
    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 MMDT5211W, opens in a new tab
  • PEC3203C2Cprinted BBSOT-323ESD protection diode, 3 pins, Panjit

    Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Panjit
    Package
    SOT-323
    Pins
    3
    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 PEC3203C2C, opens in a new tab
  • PEC3203CSprinted BBSOD-323ESD protection diode, 2 pins, Panjit

    Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    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 PEC3203CS, opens in a new tab
  • PEC3203ESprinted BBSOD-523ESD protection diode, 2 pins, Panjit

    Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Panjit
    Package
    SOD-523
    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 PEC3203ES, opens in a new tab
  • PMEG6010ERprinted BBSOD-123WSchottky diode, 2 pins, Nexperia

    Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Schottky diode
    Maker
    Nexperia
    Package
    SOD-123W
    Pins
    2
    Details
    60 V, 1 A low VF Schottky barrier rectifier
    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 PMEG6010ER, opens in a new tab
  • PUMB17printed B8SOT-363Digital transistor (PNP, resistors built in), 6 pins, Nexperia

    Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Nexperia
    Package
    SOT-363
    Pins
    6
    Details
    50 V, 100 mA PNP/PNP resistor-equipped transistor; R1 = 47 kΩ, R2 = 22 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 PUMB17, opens in a new tab
  • PUMB18printed B8SOT-363Digital transistor (PNP, resistors built in), 6 pins, Nexperia

    Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Nexperia
    Package
    SOT-363
    Pins
    6
    Details
    50 V, 100 mA PNP/PNP resistor-equipped transistor; R1 = 4.7 kΩ, R2 = 10 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 PUMB18, opens in a new tab
  • 10 more parts have no package on record
    • BAR81Wprinted BBPIN diode, Infineon

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      PIN 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 0.6 to 0.9 V anode to cathode, 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.
      • 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 varicap that has drifted in capacitance reads normal on a meter. Only a capacitance meter or the tuning itself shows 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 BAR81W, opens in a new tab
    • BB555printed BBInfineon

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

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

      Is it dead?

      Diode range and ohms range, part lifted.

      Working, it reads

      Depends on what it is. The datasheet, or an identical part, says.

      Dead, it reads

      • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
      • Open between every pair of pins: failed open, or a part that reads open when working.
      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.

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

      Datasheetfor BB555, opens in a new tab
    • BBY58-07L4printed B8Infineon

      Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

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

      Is it dead?

      Diode range and ohms range, part lifted.

      Working, it reads

      Depends on what it is. The datasheet, or an identical part, says.

      Dead, it reads

      • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
      • Open between every pair of pins: failed open, or a part that reads open when working.
      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.

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

      Datasheetfor BBY58-07L4, opens in a new tab
    • BCW61Bprinted BBTransistor, Infineon

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      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 BCW61B, opens in a new tab
    • BZT52C3V0Kprinted B8Zener diode, Taiwan Semiconductor

      Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      Zener diode
      Maker
      Taiwan Semiconductor
      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 BZT52C3V0K, opens in a new tab
    • BZX884B22Lprinted BBZener diode, Vishay

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      Zener diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      22 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 BZX884B22L, opens in a new tab
    • ESDBNB8V0A1printed B8ESD protection diode, JSCJ

      Printed B8 on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      ESD protection diode
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      ESD protection diode, VRWM 8 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 ESDBNB8V0A1, opens in a new tab
    • PEC3203C2Eprinted BBESD protection diode, Panjit

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      ESD protection diode
      Maker
      Panjit
      Package
      Not recorded
      Pins
      Not recorded
      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 PEC3203C2E, opens in a new tab
    • TLV70710DQNprinted BBLDO regulator, 4 pins, Texas Instruments

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      Texas Instruments
      Package
      Not recorded
      Pins
      4
      Details
      200-mA, Low-IQ, Low-Noise, Low-Dropout Regulator for Portable Devices
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage, board powered, black probe on ground. Then ohms with the power off.

      Working, it reads

      Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

      Dead, it reads

      • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
      • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
      • Power off, input to output near 0 Ω: shorted.
      On the board:
      An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
      Compare:
      The same regulator on another rail or another board shows the right voltages and the right resistances.
      Watch for:
      Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

      Datasheetfor TLV70710DQN, opens in a new tab
    • TSS0230Uprinted BBSchottky diode, Taiwan Semiconductor

      Printed BB on the part. Easy to misread as 88. Check that character with a loupe before you order anything.

      What it is
      Schottky diode
      Maker
      Taiwan Semiconductor
      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 0.15 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 TSS0230U, opens in a new tab
9 more parts have codes that begin with 88

Codes that begin with 88

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

  • CJ8810printed 8810SOT-23N-channel MOSFET, 3 pins, JSCJ

    Printed 8810. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    N-channel MOSFET
    Maker
    JSCJ
    Package
    SOT-23
    Pins
    3
    Details
    MOSFET, N-channel, 20 V, 7 A
    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 source, black on the drain: 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. A drain short can be the load. 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 CJ8810, opens in a new tab
  • CJ8820printed 8820SOT-23N-channel MOSFET, 3 pins, JSCJ

    Printed 8820. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    N-channel MOSFET
    Maker
    JSCJ
    Package
    SOT-23
    Pins
    3
    Details
    MOSFET, N-channel, 20 V, 7 A
    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 source, black on the drain: 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. A drain short can be the load. 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 CJ8820, opens in a new tab
  • 74AHCT1G02DCKprinted BB3SOT-353Logic gate, 5 pins, Texas Instruments

    Printed BB3. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    SOT-353
    Pins
    5
    Details
    Single 2-Input Positive-NOR GateSN74AHCT1G02 Single 2-Input Positive-NOR Gate
    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 74AHCT1G02DCK, opens in a new tab
  • 74AHCT1G86DBVprinted B86GSOT-23-5Logic gate, 5 pins, Texas Instruments

    Printed B86G. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    SOT-23-5
    Pins
    5
    Details
    Single 2-Input Exclusive-OR Gate
    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 74AHCT1G86DBV, opens in a new tab
  • BSS84printed B84SOT-23P-channel MOSFET, 3 pins, JSCJ

    Printed B84. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    P-channel MOSFET
    Maker
    JSCJ
    Package
    SOT-23
    Pins
    3
    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 BSS84, opens in a new tab
  • BSS84Wprinted B84SOT-323MOSFET, 3 pins, Taiwan Semiconductor

    Printed B84. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    MOSFET
    Maker
    Taiwan Semiconductor
    Package
    SOT-323
    Pins
    3
    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 BSS84W, opens in a new tab
  • SN74AHCT1G02DCKprinted BB3SOT-353Logic gate, 5 pins, Texas Instruments

    Printed BB3. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    SOT-353
    Pins
    5
    Details
    Single 2-Input Positive-NOR GateSN74AHCT1G02 Single 2-Input Positive-NOR Gate
    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 SN74AHCT1G02DCK, opens in a new tab
  • SN74AHCT1G86DBVprinted B863SOT-23-5Logic gate, 5 pins, Texas Instruments

    Printed B863. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    SOT-23-5
    Pins
    5
    Details
    Single 2-Input Exclusive-OR Gate
    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 SN74AHCT1G86DBV, opens in a new tab
  • 1 more part has no package on record
    • PLZ8V2Bprinted 8B2Zener diode, Vishay

      Printed 8B2. 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
      8.2 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 PLZ8V2B, opens in a new tab

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