Skip to content

SMD code search: identify a part by its marking

2 parts are printed SOS. 57 printed with a similar-looking code.

Not sure which one you have?

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

all SOT-89-5, 5 pins. What differs:

  • S-1172B27-U5T1SOT-89-5ABLICNot recordedABLIC
    What it is
    Not recorded
    Maker
    ABLIC
    Package
    SOT-89-5
    Pins
    5
    Details
    equivalent [2.7V LDO]
    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.

  • S-1172B27-U5T1GSOT-89-5LDO regulator, Seiko InstrumentsLDO regulatorSeiko Instruments
    What it is
    LDO regulator
    Maker
    Seiko Instruments
    Package
    SOT-89-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 2.7V±1%, 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.

57 more parts are printed with a code easy to misread as SOS

Printed with a code easy to misread

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

  • ACGRC505-HFprinted 505SMCRectifier, 2 pins, ComchipRectifierSMC2 pinsComchip

    Printed 505 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Rectifier
    Maker
    Comchip
    Package
    SMC
    Pins
    2
    Details
    600 V, 5 A rectifier
    Source
    Manufacturer datasheet

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board
    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.

  • ET5H150Sprinted 50SSOT-23LDO regulator, 3 pins, ETEKLDO regulatorSOT-233 pinsETEK

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ETEK
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer 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.

  • ET5H250Sprinted 50SSOT-23LDO regulator, 3 pins, ETEKLDO regulatorSOT-233 pinsETEK

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ETEK
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer 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.

  • ET5H550Sprinted 50SSOT-23LDO regulator, 3 pins, ETEKLDO regulatorSOT-233 pinsETEK

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ETEK
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer 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.

  • ET5H750Sprinted 50SSOT-23LDO regulator, 3 pins, ETEKLDO regulatorSOT-233 pinsETEK

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ETEK
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer 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.

  • ET6H150Sprinted 50SSOT-23LDO regulator, 3 pins, ETEKLDO regulatorSOT-233 pinsETEK

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ETEK
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer 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.

  • ET7H250Sprinted 50SSOT-23LDO regulator, 3 pins, ETEKLDO regulatorSOT-233 pinsETEK

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ETEK
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer 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.

  • N052AT23A-Hprinted S05SOT-23ESD protection diode, 3 pins, Formosa MicrosemiESD protection diodeSOT-233 pinsFormosa Microsemi

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Formosa Microsemi
    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.

  • PJS6405printed S05SOT-23MOSFET, 3 pins, PanjitMOSFETSOT-233 pinsPanjit

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    MOSFET
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    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.

  • AP7315-30SR-7printed 5DSSOT-23LDO regulator, 3 pins, Diodes IncorporatedLDO regulatorSOT-233 pinsDiodes Incorporated

    Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Diodes Incorporated
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 3.0V±1%, 150mA
    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.

  • AP7315D-30W5-7printed 5DSSOT-23-5LDO regulator, 5 pins, Diodes IncorporatedLDO regulatorSOT-23-55 pinsDiodes Incorporated

    Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Diodes Incorporated
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 3.0V±1%, 150mA, +CE, CL
    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.

  • FJX3005Rprinted S05SOT-323Digital transistor (NPN, resistors built in), 3 pins, Fairchild SemiconductorDigital transistor (NPN, resistors built in)SOT-3233 pinsFairchild Semiconductor

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Digital transistor (NPN, resistors built in)
    Maker
    Fairchild Semiconductor
    Package
    SOT-323
    Pins
    3
    Details
    NPN transistor: Sw, 50V, 100mA, 200mW, R1/R2=4.7k/10k
    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.

  • IXD3236A35CER-Gprinted 5D5USP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    IXYS
    Package
    USP-6C
    Pins
    6
    Details
    DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.5V±2%, 600mA, 1.2MHz, Vin>2V, LSST
    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.

  • IXD3236A35CMR-Gprinted 5D5SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    IXYS
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.5V±2%, 600mA, 1.2MHz, Vin>2V, LSST
    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.

  • IXD5127C22DMRprinted 5DSSOT-23-5Voltage supervisor, 5 pins, IXYSVoltage supervisorSOT-23-55 pinsIXYS

    Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    IXYS
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.2V±0.8%, -Reset PPO, -MR, Rdt=400ms
    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.

  • LN61FN6012Mprinted S05SOT-23Voltage supervisor, 3 pins, Shanghai Natlinear ElectronicsVoltage supervisorSOT-233 pinsShanghai Natlinear Electronics

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 6.0V±2%, +Reset ODO, Rdt=200ms
    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.

  • LN61FN6012Pprinted S05SOT-89Voltage supervisor, 3 pins, Shanghai Natlinear ElectronicsVoltage supervisorSOT-893 pinsShanghai Natlinear Electronics

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-89
    Pins
    3
    Details
    Voltage detector IC: 6.0V±2%, +Reset ODO, 200ms Rt delay
    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.

  • LN3526N5012Mprinted 505SOT-143Voltage supervisor, 4 pins, Shanghai Natlinear ElectronicsVoltage supervisorSOT-1434 pinsShanghai Natlinear Electronics

    Printed 505 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-143
    Pins
    4
    Details
    Voltage detector IC: 5.0V±2%, -Reset ODO, -MR, 200ms Rt delay
    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.

  • MMBZ5250SPTprinted 50SSOT-23Zener diode, 3 pins, Chenmko EnterpriseZener diodeSOT-233 pinsChenmko Enterprise

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Chenmko Enterprise
    Package
    SOT-23
    Pins
    3
    Details
    Zener diode: 19.60..20.40V, Izt=5mA, Zzt=48, 225mW
    Source
    Published code list

    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
    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.

  • MMCZ5250SPTprinted 50SSOT-23Zener diode, 3 pins, Chenmko EnterpriseZener diodeSOT-233 pinsChenmko Enterprise

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Chenmko Enterprise
    Package
    SOT-23
    Pins
    3
    Details
    Zener diode: 19.60..20.40V, Izt=5mA, Zzt=48, 225mW
    Source
    Published code list

    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
    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.

  • MMHZ5250SPTprinted 50SSOD-123Zener diode, 2 pins, Chenmko EnterpriseZener diodeSOD-1232 pinsChenmko Enterprise

    Printed 50S on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Chenmko Enterprise
    Package
    SOD-123
    Pins
    2
    Details
    Zener diode: 19.60..20.40V, Izt=5mA, Zzt=48, 225mW
    Source
    Published code list

    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
    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.

  • NCP300HSN30T1printed SDSSOT-23-5Voltage supervisor, 5 pins, onsemiVoltage supervisorSOT-23-55 pinsonsemi

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

    What it is
    Voltage supervisor
    Maker
    onsemi
    Package
    SOT-23-5
    Pins
    5
    Details
    CMOS-IC: Voltage Detector 3V, Reset Push-pull output
    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.

  • R1191N105Bprinted 505SOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh

    Printed 505 on the part. Easy to misread as SOS. 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, 10.5V±1.5%, 300mA, +CE, ECO
    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.

  • R3134N25EAprinted S0SSOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh

    Printed S0S on the part. Easy to misread as SOS. 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: 2.5V±1.8%, -Reset ODO, -MR
    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.

  • RP100N211Bprinted 50SSOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh

    Printed 50S on the part. Easy to misread as SOS. 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, LN, 2.1V±0.8%, 200mA, +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.

  • S505Tprinted 505SOT-143RF amplifier (MMIC), 4 pins, VishayRF amplifier (MMIC)SOT-1434 pinsVishay

    Printed 505 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    RF amplifier (MMIC)
    Maker
    Vishay
    Package
    SOT-143
    Pins
    4
    Details
    biased dg mosfet MOSIC 5V uhf tv tuners
    Source
    Published code list

    Is it dead?

    Voltage, board powered, on the output pin that the bias resistor or choke feeds.

    Working, it reads

    The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.

    Dead, it reads

    • Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
    • Output pin at the full supply voltage: open inside, no current flowing.
    On the board:
    Measured on the board with power on; the bias network is part of the reading.
    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 figures depend on the part and its bias resistor. The datasheet gives both.

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

  • SGM2200-4.4YN3LGprinted SD5SOT-89LDO regulator, 3 pins, SG MicroLDO regulatorSOT-893 pinsSG Micro

    Printed SD5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-89
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 4.4V±3%, 50mA
    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.

  • SST505printed 505SOT-233 pins, CalogicNot recordedSOT-233 pinsCalogic

    Printed 505 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Calogic
    Package
    SOT-23
    Pins
    3
    Details
    Current regulator diode
    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.

  • SST5465printed SO5SOT-233 pins, CalogicNot recordedSOT-233 pinsCalogic

    Printed SO5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Calogic
    Package
    SOT-23
    Pins
    3
    Details
    2N5465
    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.

  • TC51N6002ECBprinted S05SOT-23Voltage supervisor, 3 pins, MicrochipVoltage supervisorSOT-233 pinsMicrochip

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Microchip
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 6.0V±2%, -Reset ODO, Rdt=50..200ms
    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.

  • TC595302ECBprinted 5D5SOT-23LDO regulator, 3 pins, MicrochipLDO regulatorSOT-233 pinsMicrochip

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Microchip
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, -5.3V±2%, 200mA
    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.

  • UM1430S-25printed 5Q5SOT-23LDO regulator, 3 pins, Union SemiconductorLDO regulatorSOT-233 pinsUnion Semiconductor

    Printed 5Q5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Union Semiconductor
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 2.5V±3%, 30mA
    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.

  • UM1430S-43printed 5QSSOT-23LDO regulator, 3 pins, Union SemiconductorLDO regulatorSOT-233 pinsUnion Semiconductor

    Printed 5QS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Union Semiconductor
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 4.3V±3%, 30mA
    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.

  • UM15325Yprinted 5D5SOT-89LDO regulator, 3 pins, Union SemiconductorLDO regulatorSOT-893 pinsUnion Semiconductor

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Union Semiconductor
    Package
    SOT-89
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 2.5V±2%, 100mA
    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.

  • UM37550Sprinted 5DSSOT-23-5LDO regulator, 5 pins, Union SemiconductorLDO regulatorSOT-23-55 pinsUnion Semiconductor

    Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Union Semiconductor
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 5.0V±2%, 300mA, +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.

  • UTC8150-5printed 50-5SOT-23Voltage supervisor, 3 pins, UnisonicVoltage supervisorSOT-233 pinsUnisonic

    Printed 50-5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Unisonic
    Package
    SOT-23
    Pins
    3
    Details
    Lin/Digi-IC: Voltage Detector 5V, -Reset Open collector output
    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.

  • XC61FN6012Mprinted S05SOT-23Voltage supervisor, 3 pins, TorexVoltage supervisorSOT-233 pinsTorex

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-23
    Pins
    3
    Details
    CMOS-IC: Voltage Detector 6V, Reset Open drain output, 200ms
    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.

  • XC61FN6012Pprinted S05SOT-89Voltage supervisor, 3 pins, TorexVoltage supervisorSOT-893 pinsTorex

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-89
    Pins
    3
    Details
    CMOS-IC: Voltage Detector 6V, Reset Open drain output, 200ms
    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.

  • XC61HN6012MRprinted S05SOT-23Voltage supervisor, 3 pins, TorexVoltage supervisorSOT-233 pinsTorex

    Printed S05 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 6.0V±2%, -Reset ODO, Rdt=50..200ms
    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.

  • XC62KN532Mprinted 5D5SOT-23LDO regulator, 3 pins, TorexLDO regulatorSOT-233 pinsTorex

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Torex
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, -5.3V±2%, 100mA, 150mW
    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.

  • XC62KN532Pprinted 5D5SOT-89LDO regulator, 3 pins, TorexLDO regulatorSOT-893 pinsTorex

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Torex
    Package
    SOT-89
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, -5.3V±2%, 100mA, 500mW
    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.

  • XC6106D024MRprinted 5DSSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex

    Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-23-5
    Pins
    5
    Details
    CMOS-IC: VDet 2.4V, 5%, Hst, -MR, ±Reset PPO, Rt=100ms
    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.

  • XC6106D036MRprinted 5D5SOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex

    Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-23-5
    Pins
    5
    Details
    CMOS-IC: VDet 3.6V, 5%, Hst, -MR, ±Reset PPO, Rt=100ms
    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.

  • XC6127C22DMRprinted 5DSSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex

    Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.2V±0.8%, -Reset PPO, -MR, Rdt=400ms
    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.

  • XC6371E350Pprinted SD5SOT-89-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-89-55 pinsTorex

    Printed SD5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Torex
    Package
    SOT-89-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PWM st-up, 50kHz, 3.5V±2.5%, 100mA, int. Vdd
    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.

  • 3 more parts have no package on record
    • AP7315D-30FS4-7Bprinted 5DSLDO regulator, Diodes IncorporatedLDO regulatorNot recordedNot recordedDiodes Incorporated

      Printed 5DS on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      Diodes Incorporated
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 3.0V±1%, 150mA, +CE, CL
      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.

    • IXD3236A35C0R-Gprinted 5D5DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

      What it is
      DC-DC converter
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.5V±2%, 600mA, 1.2MHz, Vin>2V, LSST
      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.

    • IXD3236A35C4R-Gprinted 5D5DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed 5D5 on the part. Easy to misread as SOS. Check that character with a loupe before you order anything.

      What it is
      DC-DC converter
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.5V±2%, 600mA, 1.2MHz, Vin>2V, LSST
      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.

9 more parts are not listed here. Type more of the code to narrow the list.

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.

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: 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.

  • Get WhatSMD on Google Play
  • Coming soon to the App Store