WhatSMD: identify an unknown SMD component

Not sure which one you have?

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

The only part printed 12 in this package in our tables

TLV74012PDQN

What it is: LDO regulator
Maker: Texas Instruments
Package: Not recorded
Pins: 4
Details: 300mA, Low-Dropout Regulator With Foldback Current Limit
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.

Datasheet

Printed with a code easy to misread

These parts are printed with a character that is easy to misread as what you typed. The odd one out is marked on each.

CESDLC5V0K5printed L2SOT-363ESD protection diode, 6 pins, JSCJESD protection diode6 pinsJSCJ
Printed L2 on the part. Easy to misread as 12. Check that character with a loupe before you order anything.
What it is
ESD protection diode
Maker
JSCJ
Package
SOT-363
Pins
6
Details
ESD protection diode, VRWM 5 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 CESDLC5V0K5, opens in a new tab
2 more parts have no package on record. Nothing rules them out, so they stay.
- BCR402Uprinted L2Digital transistor (resistors built in), InfineonDigital transistor (resistors built in)Not recordedInfineon
  Printed L2 on the part. Easy to misread as 12. 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 BCR402U, opens in a new tab
- TLV809EA26DPWprinted IZVoltage supervisor, 5 pins, Texas InstrumentsVoltage supervisor5 pinsTexas Instruments
  Printed IZ on the part. Easy to misread as 12. 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 TLV809EA26DPW, opens in a new tab

46 more parts have codes that begin with 12

Codes that begin with 12

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

1SMB3EZ12printed 12BZener diode, PanjitZener diodeNot recordedPanjit
Printed 12B. 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 1SMB3EZ12, opens in a new tab
1SMB3EZ12-AUprinted 12BZener diode, PanjitZener diodeNot recordedPanjit
Printed 12B. 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 1SMB3EZ12-AU, opens in a new tab
CJM1216printed 1216P-channel MOSFET, JSCJP-channel MOSFETNot recordedJSCJ
Printed 1216. 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
Not recorded
Pins
Not recorded
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 CJM1216, opens in a new tab
ESDH12VP1printed 12HESD protection diode, JSCJESD protection diodeNot recordedJSCJ
Printed 12H. 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 12 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 ESDH12VP1, opens in a new tab
ESDQ12VFD1Uprinted 12UESD protection diode, JSCJESD protection diodeNot recordedJSCJ
Printed 12U. 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 12 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 ESDQ12VFD1U, opens in a new tab
PLZ12Aprinted 12AZener diode, VishayZener diodeNot recordedVishay
Printed 12A. 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
12 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 PLZ12A, opens in a new tab
PLZ12Bprinted 12BZener diode, VishayZener diodeNot recordedVishay
Printed 12B. 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
12 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 PLZ12B, opens in a new tab
PLZ12Cprinted 12CZener diode, VishayZener diodeNot recordedVishay
Printed 12C. 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
12 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 PLZ12C, opens in a new tab
SS120ALHprinted 120ALHSchottky diode, Taiwan SemiconductorSchottky diodeNot recordedTaiwan Semiconductor
Printed 120ALH. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Schottky diode
Maker
Taiwan Semiconductor
Package
Not recorded
Pins
Not recorded
Details
Rectifier schottky
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 SS120ALH, opens in a new tab
TPS561201DDCprinted 1201DC DC converter, 6 pins, Texas InstrumentsDC DC converter6 pinsTexas Instruments
Printed 1201. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
DC DC converter
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
4.5-V to 17-V Input, 1-A Synchronous Step-Down Voltage Regulator in 6- Pin SOT-23
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 TPS561201DDC, opens in a new tab
TPS561208DDCprinted 1208DC DC converter, 6 pins, Texas InstrumentsDC DC converter6 pinsTexas Instruments
Printed 1208. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
DC DC converter
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
4.5-V to 17-V Input, 1-A Synchronous Step-Down Voltage Regulator in 6- Pin SOT-23
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 TPS561208DDC, opens in a new tab
AOI294Aprinted I294AMOSFET, Alpha & Omega SemiconductorMOSFETNot recordedAlpha & Omega Semiconductor
Printed I294A. 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
Alpha & Omega Semiconductor
Package
Not recorded
Pins
Not recorded
Details
Medium-voltage (40-400 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 AOI294A, opens in a new tab
AOI296Aprinted I296AMOSFET, Alpha & Omega SemiconductorMOSFETNot recordedAlpha & Omega Semiconductor
Printed I296A. 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
Alpha & Omega Semiconductor
Package
Not recorded
Pins
Not recorded
Details
Medium-voltage (40-400 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 AOI296A, opens in a new tab
AOI2610Eprinted I2610EMOSFET, Alpha & Omega SemiconductorMOSFETNot recordedAlpha & Omega Semiconductor
Printed I2610E. 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
Alpha & Omega Semiconductor
Package
Not recorded
Pins
Not recorded
Details
Medium-voltage (40-400 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 AOI2610E, opens in a new tab
AOI21357printed I21357P-channel MOSFET, Alpha & Omega SemiconductorP-channel MOSFETNot recordedAlpha & Omega Semiconductor
Printed I21357. 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
Alpha & Omega Semiconductor
Package
Not recorded
Pins
Not recorded
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 AOI21357, opens in a new tab
INA186A1IDDFprinted 1ZLWCurrent sense amplifier, 8 pins, Texas InstrumentsCurrent sense amplifier8 pinsTexas Instruments
Printed 1ZLW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Current sense amplifier
Maker
Texas Instruments
Package
Not recorded
Pins
8
Details
Bidirectional, Low-Power, Zero-Drift, Wide Dynamic Range, Current-Sense Amplifier With Enable
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 INA186A1IDDF, opens in a new tab
INA186A2IDDFprinted 1ZMWCurrent sense amplifier, 8 pins, Texas InstrumentsCurrent sense amplifier8 pinsTexas Instruments
Printed 1ZMW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Current sense amplifier
Maker
Texas Instruments
Package
Not recorded
Pins
8
Details
Bidirectional, Low-Power, Zero-Drift, Wide Dynamic Range, Current-Sense Amplifier With Enable
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 INA186A2IDDF, opens in a new tab
INA186A3IDDFprinted 1ZNWCurrent sense amplifier, 8 pins, Texas InstrumentsCurrent sense amplifier8 pinsTexas Instruments
Printed 1ZNW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Current sense amplifier
Maker
Texas Instruments
Package
Not recorded
Pins
8
Details
Bidirectional, Low-Power, Zero-Drift, Wide Dynamic Range, Current-Sense Amplifier With Enable
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 INA186A3IDDF, opens in a new tab
INA186A4IDDFprinted 1ZOWCurrent sense amplifier, 8 pins, Texas InstrumentsCurrent sense amplifier8 pinsTexas Instruments
Printed 1ZOW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Current sense amplifier
Maker
Texas Instruments
Package
Not recorded
Pins
8
Details
Bidirectional, Low-Power, Zero-Drift, Wide Dynamic Range, Current-Sense Amplifier With Enable
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 INA186A4IDDF, opens in a new tab
INA186A5IDDFprinted 1ZPWCurrent sense amplifier, 8 pins, Texas InstrumentsCurrent sense amplifier8 pinsTexas Instruments
Printed 1ZPW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Current sense amplifier
Maker
Texas Instruments
Package
Not recorded
Pins
8
Details
Bidirectional, Low-Power, Zero-Drift, Wide Dynamic Range, Current-Sense Amplifier With Enable
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 INA186A5IDDF, opens in a new tab
PZ1AFC2V5Bprinted 1Z2V5BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z2V5B. 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 PZ1AFC2V5B, opens in a new tab
PZ1AFC3V6Bprinted 1Z3V6BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z3V6B. 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 PZ1AFC3V6B, opens in a new tab
PZ1AFC3V9Bprinted 1Z3V9BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z3V9B. 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 PZ1AFC3V9B, opens in a new tab
PZ1AFC4V3Bprinted 1Z4V3BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z4V3B. 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 PZ1AFC4V3B, opens in a new tab
PZ1AFC4V7Bprinted 1Z4V7BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z4V7B. 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 PZ1AFC4V7B, opens in a new tab
PZ1AFC5V1Bprinted 1Z5V1BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z5V1B. 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 PZ1AFC5V1B, opens in a new tab
PZ1AFC5V6Bprinted 1Z5V6BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z5V6B. 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 PZ1AFC5V6B, opens in a new tab
PZ1AFC6V0Bprinted 1Z6V0BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z6V0B. 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 PZ1AFC6V0B, opens in a new tab
PZ1AFC6V2Bprinted 1Z6V2BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z6V2B. 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 PZ1AFC6V2B, opens in a new tab
PZ1AFC6V8Bprinted 1Z6V8BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z6V8B. 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 PZ1AFC6V8B, opens in a new tab
PZ1AFC7V5Bprinted 1Z7V5BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z7V5B. 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 PZ1AFC7V5B, opens in a new tab
PZ1AFC8V2Bprinted 1Z8V2BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z8V2B. 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 PZ1AFC8V2B, opens in a new tab
PZ1AFC8V7Bprinted 1Z8V7BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z8V7B. 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 PZ1AFC8V7B, opens in a new tab
PZ1AFC9V1Bprinted 1Z9V1BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z9V1B. 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 PZ1AFC9V1B, opens in a new tab
PZ1AFC10Bprinted 1Z10BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z10B. 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 PZ1AFC10B, opens in a new tab
PZ1AFC11Bprinted 1Z11BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z11B. 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 PZ1AFC11B, opens in a new tab
PZ1AFC12Bprinted 1Z12BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z12B. 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 PZ1AFC12B, opens in a new tab
PZ1AFC13Bprinted 1Z13BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z13B. 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 PZ1AFC13B, opens in a new tab
PZ1AFC14Bprinted 1Z14BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z14B. 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 PZ1AFC14B, opens in a new tab
PZ1AFC15Bprinted 1Z15BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z15B. 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 PZ1AFC15B, opens in a new tab
PZ1AFC16Bprinted 1Z16BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z16B. 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 PZ1AFC16B, opens in a new tab
PZ1AFC17Bprinted 1Z17BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z17B. 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 PZ1AFC17B, opens in a new tab
PZ1AFC18Bprinted 1Z18BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z18B. 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 PZ1AFC18B, opens in a new tab
PZ1AFC19Bprinted 1Z19BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z19B. 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 PZ1AFC19B, opens in a new tab
PZ1AFC20Bprinted 1Z20BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z20B. 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 PZ1AFC20B, opens in a new tab
PZ1AFC22Bprinted 1Z22BZener diode, PanjitZener diodeNot recordedPanjit
Printed 1Z22B. 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 PZ1AFC22B, opens in a new tab

One code, several parts

Marking codes are not unique. In the standard code book, 6H on a SOT-23 is an NPN transistor, a varicap, an N-channel JFET, two digital transistors, a 3.6 V voltage detector: six parts from five makers. So a search shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.

6Hon a SOT-23, in the code book

NPN transistor
Varicap
N-channel JFET
Digital transistor ×2
3.6 V voltage detector

When more than one is left

Tap Help me choose. Up to 4 quick answers: whether the part has failed, then what separates the parts left. Those get ranked with the reasoning and a test that settles it. That uses one identification; 3 a month are free.

When you cannot read it

Tap the camera in the field. We read the characters, keep the ones we are unsure of, and search every reading. A photo too soft to read is turned back on your phone first; if it is the only one you can get, you can still send it.

What’s printed on it?

TLV74012PDQN

Is it dead?

Printed with a code easy to misread

Is it dead?

Is it dead?

Is it dead?

Codes that begin with 12

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

One code, several parts

When more than one is left

When you cannot read it