SMD code search: identify a part by its marking
1 part is printed WO2. 9 printed with a similar-looking code.
Not sure which one you have?
Answer up to 4 quick questions and these 10 parts are ranked, with a meter test that settles it. It works on a dead part too.
The only part printed WO2 in our tables
BAV20WS
- What it is
- Switching diode
- Maker
- FutureWafer Tech
- Package
- SOD-323
- Pins
- 2
- Source
- Published code list
Is it dead?
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- Open both ways: failed open.
- A reading the wrong way round as well: leaky.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Was it this one?
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.
JEU05UCT2Bprinted W02SOT-23TVS diode, 3 pins, JieJieTVS diodeSOT-233 pinsJieJie
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- TVS diode
- Maker
- JieJie
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer 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
- , 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.
JEU05UCT2B-AUprinted W02SOT-23TVS diode, 3 pins, JieJieTVS diodeSOT-233 pinsJieJie
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- TVS diode
- Maker
- JieJie
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer 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
- , 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.
PDTC143ETprinted W02SOT-23Digital transistor (NPN, resistors built in), 3 pins, NXPDigital transistor (NPN, resistors built in)SOT-233 pinsNXP
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- NXP
- Package
- SOT-23
- Pins
- 3
- Details
- 50 V, 100 mA NPN resistor-equipped transistor; R1 = 4.7 kOhm, R2 = 4.7 kOhm
- Source
- Published code list
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
- 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.
PDTC143EUprinted W02SOT-323Digital transistor (NPN, resistors built in), 3 pins, NXPDigital transistor (NPN, resistors built in)SOT-3233 pinsNXP
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- NXP
- Package
- SOT-323
- Pins
- 3
- Details
- 50 V, 100 mA NPN resistor-equipped transistor; R1 = 4.7 kΩ, R2 = 4.7 kΩ
- Source
- Published code list
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
- 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.
PMV48XPAprinted WDZSOT-233 pins, NexperiaNot recordedSOT-233 pinsNexperia
Printed WDZ on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Nexperia
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
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
- 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.
R1155N102Bprinted W02SOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 10.2V±2%, 150mA, +CE, Test
- Source
- Published code list
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.
R3119N068Aprinted W0ZSOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W0Z on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 6.8V±1.5%, -Reset ODO
- Source
- Published code list
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.
2 more parts have no package on record
TC07W02FKprinted W02Logic gate, ToshibaLogic gateNot recordedNot recordedToshiba
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- Logic gate
- Maker
- Toshiba
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Dual 2-Input NOR Gate
- Source
- Published code list
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.
TC7W02FKprinted W02ToshibaNot recordedNot recordedNot recordedToshiba
Printed W02 on the part. Easy to misread as WO2. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Toshiba
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS logic IC: Dual 2-input NOR gate
- Source
- Published code list
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.
23 more parts have codes that begin with WO2
Codes that begin with WO2
For a marking with its end worn or burnt off. Each one shows its full printed code.
WEOS4-100/15ASprinted W02SCSMB2 pins, WayonNot recordedSMB2 pinsWayon
Printed W02SC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Wayon
- Package
- SMB
- Pins
- 2
- Details
- Thyristor surge protector (TSS)
- Source
- Manufacturer 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
- 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.
WMW02N15TSprinted W02N15SSOT-893 pins, WayonNot recordedSOT-893 pinsWayon
Printed W02N15S. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Wayon
- Package
- SOT-89
- Pins
- 3
- Details
- MOSFET
- Source
- Manufacturer 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
- 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.
R1190H020Bprinted W020SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W020. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.0V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H021Bprinted W021SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W021. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.1V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H022Bprinted W022SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W022. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.2V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H023Bprinted W023SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W023. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.3V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H024Bprinted W024SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W024. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.4V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H025Bprinted W025SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W025. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.5V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H026Bprinted W026SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W026. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.6V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H027Bprinted W027SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W027. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.7V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H028Bprinted W028SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W028. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.8V±1.5%, 1A, +CE
- Source
- Published code list
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.
R1190H029Bprinted W029SOT-89-55 pins, RicohNot recordedSOT-89-55 pinsRicoh
Printed W029. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-89-5
- Pins
- 5
- Details
- Linear voltage regulator IC: 2.9V±1.5%, 1A, +CE
- Source
- Published code list
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.
R3111Q202Bprinted W020SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W020. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.0V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q212Bprinted W021SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W021. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.1V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q222Bprinted W022SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W022. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.2V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q232Bprinted W023SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W023. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.3V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q242Bprinted W024SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W024. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.4V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q252Bprinted W025SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W025. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.5V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q262Bprinted W026SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W026. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.6V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q272Bprinted W027SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W027. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.7V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q282Bprinted W028SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W028. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.8V±2%, +Reset ODO
- Source
- Published code list
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.
R3111Q292Bprinted W029SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed W029. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.9V±2%, +Reset ODO
- Source
- Published code list
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.
1 more part has no package on record
WEOS4-150/15ASprinted W02SDWayonNot recordedNot recordedNot recordedWayon
Printed W02SD. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Wayon
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Thyristor surge protector (TSS)
- Source
- Manufacturer 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
- 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.
Did you find your part?
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.
- 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: 2 a month are free without an account, and 3 with a free account.
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.
Get the app
The same search on your phone, and a camera with a light, zoom and tap to focus for a marking you cannot read. Sign in with your email address to use the same account.
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