Skip to content

SMD code search: identify a part by its marking

2 parts are printed 1Q1. 140 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.

  • SGM2240-12XKC3GSOT-223LDO regulator, 3 pins, SG MicroLDO regulatorSOT-2233 pinsSG Micro
    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-223
    Pins
    3
    Details
    12 V output, 1A, Low Dropout Positive Fixed and Adjustable Voltage Regulator
    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.

  • STZ8039ASOD-323Zener diode, 2 pins, JinYu semiconductorZener diodeSOD-3232 pinsJinYu semiconductor
    What it is
    Zener diode
    Maker
    JinYu semiconductor
    Package
    SOD-323
    Pins
    2
    Details
    Zener diode: 3.7..3.97V, Izt=5mA, Zzt=13, 300mW
    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.

140 more parts are printed with a code easy to misread as 1Q1

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.

  • ACFRA101-HFprinted 101SMARectifier, 2 pins, ComchipRectifierSMA2 pinsComchip

    Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Rectifier
    Maker
    Comchip
    Package
    SMA
    Pins
    2
    Details
    50 V, 1 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.

  • APL5101-24printed 10ISOT-23LDO regulator, 3 pins, AnpecLDO regulatorSOT-233 pinsAnpec

    Printed 10I on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Anpec
    Package
    SOT-23
    Pins
    3
    Details
    150mA, 4µA Quiescent Current Regulator
    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.

  • APL5101-27printed 10LSOT-23LDO regulator, 3 pins, AnpecLDO regulatorSOT-233 pinsAnpec

    Printed 10L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Anpec
    Package
    SOT-23
    Pins
    3
    Details
    150mA, 4µA Quiescent Current Regulator
    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.

  • RS0101YUTDV6printed 101DFNLogic level translator, RunicLogic level translatorDFNNot recordedRunic

    Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Logic level translator
    Maker
    Runic
    Package
    DFN
    Pins
    Not recorded
    Source
    Manufacturer datasheet

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • S-1312A33-M5T1U3printed 1D1SOT-23-5LDO regulator, 5 pins, ABLICLDO regulatorSOT-23-55 pinsABLIC

    Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ABLIC
    Package
    SOT-23-5
    Pins
    5
    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.

  • 2SC4083-Lprinted 1DLSOT-323RF transistor, 3 pins, ROHMRF transistorSOT-3233 pinsROHM

    Printed 1DL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    RF transistor
    Maker
    ROHM
    Package
    SOT-323
    Pins
    3
    Details
    Si-npn: VHF/UHF, 20V, 50mA, 200mW, B=27..56, 3.2GHz
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • 3.0GSMDJ7.0Cprinted IDLSMCTVS diode, 2 pins, Good-ArkTVS diodeSMC2 pinsGood-Ark

    Printed IDL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    TVS diode
    Maker
    Good-Ark
    Package
    SMC
    Pins
    2
    Details
    Transient voltage supressor: Vrwm=7.0V, Vbr=7.78..9.86V, Ipp=225.6A, 3000W(1ms), Bidir.
    Source
    Published code list

    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.

  • 3.0SMCJ7.0Cprinted IDLSMCTVS diode, 2 pins, PanjitTVS diodeSMC2 pinsPanjit

    Printed IDL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    TVS diode
    Maker
    Panjit
    Package
    SMC
    Pins
    2
    Details
    TVS: 7V, 225.6A, 3000W (1ms), Bidirectional
    Source
    Published code list

    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.

  • 3.0SMI7.0Cprinted IDLSMCTVS diode, 2 pins, SMC Diode SolutionsTVS diodeSMC2 pinsSMC Diode Solutions

    Printed IDL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    TVS diode
    Maker
    SMC Diode Solutions
    Package
    SMC
    Pins
    2
    Details
    Transient voltage supressor: Vbr=7.78..9.86V, Vrwm=7.0V, 225.6A, 3000W(1ms), Bidir.
    Source
    Published code list

    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.

  • ADM6348-39ARTZprinted LD1SOT-23Voltage supervisor, 3 pins, Analog DevicesVoltage supervisorSOT-233 pinsAnalog Devices

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Analog Devices
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 3.9V±2.5%, -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.

  • ADP1710AUJZ-Rprinted L0LSOT-23-5LDO regulator, 5 pins, Analog DevicesLDO regulatorSOT-23-55 pinsAnalog Devices

    Printed L0L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Analog Devices
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, Adjustable, 0.8..5.0V, 150mA, +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.

  • APL5101-24AIprinted 10ISOT-23LDO regulator, 3 pins, Anpec ElectronicsLDO regulatorSOT-233 pinsAnpec Electronics

    Printed 10I on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Anpec Electronics
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 2.4V±2%, 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.

  • APL5101-24BIprinted 10ISOT-23-5LDO regulator, 5 pins, Anpec ElectronicsLDO regulatorSOT-23-55 pinsAnpec Electronics

    Printed 10I on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Anpec Electronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 2.4V±2%, 150mA, +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.

  • APL5101-27AIprinted 10LSOT-23LDO regulator, 3 pins, Anpec ElectronicsLDO regulatorSOT-233 pinsAnpec Electronics

    Printed 10L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Anpec Electronics
    Package
    SOT-23
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 2.7V±2%, 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.

  • APL5101-27BIprinted 10LSOT-23-5LDO regulator, 5 pins, Anpec ElectronicsLDO regulatorSOT-23-55 pinsAnpec Electronics

    Printed 10L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Anpec Electronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 2.7V±2%, 150mA, +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.

  • BL8534CB3TR31printed LD1SOT-23DC-DC converter, 3 pins, Shanghai BellingDC-DC converterSOT-233 pinsShanghai Belling

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Shanghai Belling
    Package
    SOT-23
    Pins
    3
    Details
    DC/DC voltage converter IC: PFM st-up, 3.1V±2%, 200mA
    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.

  • BL8534CB3TR41printed LD1SOT-23DC-DC converter, 3 pins, Shanghai BellingDC-DC converterSOT-233 pinsShanghai Belling

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Shanghai Belling
    Package
    SOT-23
    Pins
    3
    Details
    DC/DC voltage converter IC: PFM st-up, 4.1V±2%, 200mA
    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.

  • BL8534CB3TR51printed LD1SOT-23DC-DC converter, 3 pins, Shanghai BellingDC-DC converterSOT-233 pinsShanghai Belling

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Shanghai Belling
    Package
    SOT-23
    Pins
    3
    Details
    DC/DC voltage converter IC: PFM st-up, 5.1V±2%, 200mA
    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.

  • BL8534CB5TR31printed LD1SOT-23-5DC-DC converter, 5 pins, Shanghai BellingDC-DC converterSOT-23-55 pinsShanghai Belling

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Shanghai Belling
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PFM st-up, 3.1V±2%, 200mA
    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.

  • BL8534CB5TR41printed LD1SOT-23-5DC-DC converter, 5 pins, Shanghai BellingDC-DC converterSOT-23-55 pinsShanghai Belling

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Shanghai Belling
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PFM st-up, 4.1V±2%, 200mA
    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.

  • BL8534CB5TR51printed LD1SOT-23-5DC-DC converter, 5 pins, Shanghai BellingDC-DC converterSOT-23-55 pinsShanghai Belling

    Printed LD1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    Shanghai Belling
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PFM st-up, 5.1V±2%, 200mA
    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.

  • CMJ0130printed 101SOD-123F2 pins, Central SemiconductorNot recordedSOD-123F2 pinsCentral Semiconductor

    Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Central Semiconductor
    Package
    SOD-123F
    Pins
    2
    Details
    Diode: Current limiter, Ilim=0.05..0.21mA, Vlmin=0.6V, 500mW
    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.

  • FM810LS3Xprinted 10LSOT-233 pins, FNot recordedSOT-233 pinsF

    Printed 10L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    F
    Package
    SOT-23
    Pins
    3
    Details
    CMOS-IC: Voltage Detector 4.63V, 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.

  • HE61CN1001MRprinted L01SOT-23Voltage supervisor, 3 pins, Heermicr SemicconductorVoltage supervisorSOT-233 pinsHeermicr Semicconductor

    Printed L01 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Heermicr Semicconductor
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 1.0V±1%, +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.

  • HE7010MNM5R1printed L01SOT-23-5Voltage supervisor, 5 pins, Heermicr SemicconductorVoltage supervisorSOT-23-55 pinsHeermicr Semicconductor

    Printed L01 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Heermicr Semicconductor
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 1.0V±1%, +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.

  • HE7010MNNR1printed L01SOT-23Voltage supervisor, 3 pins, Heermicr SemicconductorVoltage supervisorSOT-233 pinsHeermicr Semicconductor

    Printed L01 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Heermicr Semicconductor
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 1.0V±1%, +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.

  • HE7010MNPR1printed L01SOT-89Voltage supervisor, 3 pins, Heermicr SemicconductorVoltage supervisorSOT-893 pinsHeermicr Semicconductor

    Printed L01 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Heermicr Semicconductor
    Package
    SOT-89
    Pins
    3
    Details
    Voltage detector IC: 1.0V±1%, +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.

  • IXD1415AA01ER-Gprinted 101USP-6CLDO regulator, 6 pins, IXYSLDO regulatorUSP-6C6 pinsIXYS

    Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    USP-6C
    Pins
    6
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.80/2.80V±1%, 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.

  • IXD1415AA01MRprinted 101SOT-23-6LDO regulator, 6 pins, IXYSLDO regulatorSOT-23-66 pinsIXYS

    Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    SOT-23-6
    Pins
    6
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.80/2.80V±1%, 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.

  • IXD1415AAD1ER-Gprinted 1D1USP-6CLDO regulator, 6 pins, IXYSLDO regulatorUSP-6C6 pinsIXYS

    Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    USP-6C
    Pins
    6
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.00/2.85V±1%, 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.

  • IXD1415AAD1MRprinted 1D1SOT-23-6LDO regulator, 6 pins, IXYSLDO regulatorSOT-23-66 pinsIXYS

    Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    SOT-23-6
    Pins
    6
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.00/2.85V±1%, 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.

  • IXD1503D431MR-Gprinted 1D1SOT-23-5LDO regulator, 5 pins, IXYSLDO regulatorSOT-23-55 pinsIXYS

    Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 4.3V±1%, 500mA, +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.

  • IXD1503D431PR-Gprinted 1D1SOT-89-5LDO regulator, 5 pins, IXYSLDO regulatorSOT-89-55 pinsIXYS

    Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    SOT-89-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 4.3V±1%, 500mA, +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.

  • IXD1503P131PR-Gprinted 101SOT-89LDO regulator, 3 pins, IXYSLDO regulatorSOT-893 pinsIXYS

    Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    SOT-89
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 1.3V±20mV, 500mA
    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.

  • IXD1503P301PR-Gprinted 10LSOT-89LDO regulator, 3 pins, IXYSLDO regulatorSOT-893 pinsIXYS

    Printed 10L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    IXYS
    Package
    SOT-89
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 3.0V±1%, 500mA
    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.

  • 13 more parts have no package on record
    • S-1312A33-A4T1U3printed 1D1LDO regulator, ABLICLDO regulatorNot recordedNot recordedABLIC

      Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      ABLIC
      Package
      Not recorded
      Pins
      Not recorded
      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.

    • S-1312A33-A4T2U3printed 1D1LDO regulator, ABLICLDO regulatorNot recordedNot recordedABLIC

      Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      ABLIC
      Package
      Not recorded
      Pins
      Not recorded
      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.

    • S1DLprinted 1DLRectifier, Taiwan SemiconductorRectifierNot recordedNot recordedTaiwan Semiconductor

      Printed 1DL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      Rectifier
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      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.

    • S1DLHprinted 1DLRectifier, Taiwan SemiconductorRectifierNot recordedNot recordedTaiwan Semiconductor

      Printed 1DL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      Rectifier
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      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.

    • SGM2080-0.8QTGC6Gprinted 1QILDO regulator, 6 pins, SG MicroLDO regulatorNot recorded6 pinsSG Micro

      Printed 1QI on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      SG Micro
      Package
      Not recorded
      Pins
      6
      Details
      Automotive 500mA, Fast Transient Response, Noise and High Accuracy LDO with Power-Good
      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.

    • SGM2080-1.05QTGC6Gprinted 1QLLDO regulator, 6 pins, SG MicroLDO regulatorNot recorded6 pinsSG Micro

      Printed 1QL on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      SG Micro
      Package
      Not recorded
      Pins
      6
      Details
      Automotive 500mA, Fast Transient Response, Noise and High Accuracy LDO with Power-Good
      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.

    • 1PMT4101printed 101Zener diode, Microsemi Integrated Products DivisionZener diodeNot recordedNot recordedMicrosemi Integrated Products Division

      Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      Zener diode
      Maker
      Microsemi Integrated Products Division
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 8.2V±5%, Izt=100.6mA, 1W
      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.

    • ADP1710AUJZ-R7printed L0L5 pins, Analog DevicesNot recordedNot recorded5 pinsAnalog Devices

      Printed L0L on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      Not recorded
      Maker
      Analog Devices
      Package
      Not recorded
      Pins
      5
      Details
      equivalent [Adj. 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.

    • HZM10NB1printed 101Zener diode, RenesasZener diodeNot recordedNot recordedRenesas

      Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      Zener diode
      Maker
      Renesas
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Z-diode: 9.45..9.87V, 200mW
      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.

    • IXD1415AA017R-Gprinted 101LDO regulator, IXYSLDO regulatorNot recordedNot recordedIXYS

      Printed 101 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.80/2.80V±1%, 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.

    • IXD1415AAD17R-Gprinted 1D1LDO regulator, IXYSLDO regulatorNot recordedNot recordedIXYS

      Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.00/2.85V±1%, 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.

    • IXD1503D431GR-Gprinted 1D1LDO regulator, IXYSLDO regulatorNot recordedNot recordedIXYS

      Printed 1D1 on the part. Easy to misread as 1Q1. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 4.3V±1%, 500mA, +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.

    • IXD3236C3LC0R-Gprinted LDLDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed LDL on the part. Easy to misread as 1Q1. 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, 3.85V±2%, 600mA, 1.2MHz, Vin>2V, LSST, CL
      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.

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

Did you find your part?

Try Tech free for 30 days. You need a card to start. Unless you cancel during the trial, Tech then costs €12.00 a month plus VAT. See the plans

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 on WhatSMD (What SMD) 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