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SMD code search: identify a part by its marking

No part printed L51 is recorded in SOT-363. 23 printed with a similar-looking code.

Not sure which one you have?

Answer up to 4 quick questions and these 24 parts are ranked, with a meter test that settles it. It works on a dead part too.

1 part has no package on record. Nothing rules it out, so it stays.

  • ADP1713AUJZ-1.1R75 pins, Analog Devices5 pinsAnalog Devices
    What it is
    Not recorded
    Maker
    Analog Devices
    Package
    Not recorded
    Pins
    5
    Details
    equivalent [1.1V 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.

Printed with a code easy to misread

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

  • LD6991AGU-2616printed LSISOT-3636 pins, LeadtrendNot recorded6 pinsLeadtrend

    Printed LSI on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Leadtrend
    Package
    SOT-363
    Pins
    6
    Details
    Linear voltage regulator with volatge detector: LDO, 2.6V±2%, 90mA, Vdet=1.6V±2%, +Reset ODO
    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.

  • LD6991AGU-2619printed LSLSOT-3636 pins, LeadtrendNot recorded6 pinsLeadtrend

    Printed LSL on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Leadtrend
    Package
    SOT-363
    Pins
    6
    Details
    Linear voltage regulator with volatge detector: LDO, 2.6V±2%, 90mA, Vdet=1.9V±2%, +Reset ODO
    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.

  • 21 more parts have no package on record. Nothing rules them out, so they stay.
    • KIC7151T5printed 151Voltage supervisor, KECVoltage supervisorNot recordedKEC

      Printed 151 on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      Voltage supervisor
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS voltage detector, 5.1 V detection
      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-13D1B1818-A6T2U3printed 15LLDO regulator, ABLICLDO regulatorNot recordedABLIC

      Printed 15L on the part. Easy to misread as L51. 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-13D1C2J2J-A6T2U3printed 151LDO regulator, ABLICLDO regulatorNot recordedABLIC

      Printed 151 on the part. Easy to misread as L51. 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.

    • SGM2236-ADJXTDI6Gprinted 1S1LDO regulator, 6 pins, SG MicroLDO regulator6 pinsSG Micro

      Printed 1S1 on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      SG Micro
      Package
      Not recorded
      Pins
      6
      Details
      40V, 200mA, Low Quiescent Current and Low Dropout Voltage Linear 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.

    • SUESDL15V-Cprinted 15LESD protection diode, SeCoSESD protection diodeNot recordedSeCoS

      Printed 15L on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      ESD protection diode
      Maker
      SeCoS
      Package
      Not recorded
      Pins
      Not recorded
      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.

    • ADP1714AUJZ-1.2R7printed L5L5 pins, Analog DevicesNot recorded5 pinsAnalog Devices

      Printed L5L on the part. Easy to misread as L51. 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 [1.2V 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.

    • HZM15NB1printed 151Zener diode, RenesasZener diodeNot recordedRenesas

      Printed 151 on the part. Easy to misread as L51. 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: 13.84..14.46V, 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.

    • HZU15L-1printed 151Zener diode, RenesasZener diodeNot recordedRenesas

      Printed 151 on the part. Easy to misread as L51. 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: 14.1..14.7V, 150mW
      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.

    • IXD1415AA517R-Gprinted 151LDO regulator, IXYSLDO regulatorNot recordedIXYS

      Printed 151 on the part. Easy to misread as L51. 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=4.20/3.10V±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.

    • IXD3236D3LC0R-Gprinted LSLDC-DC converter, IXYSDC-DC converterNot recordedIXYS

      Printed LSL on the part. Easy to misread as L51. 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>1.8V, 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.

    • IXD3236D3LC4R-Gprinted LSLDC-DC converter, IXYSDC-DC converterNot recordedIXYS

      Printed LSL on the part. Easy to misread as L51. 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>1.8V, 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.

    • IXD3236D31C0R-Gprinted LS1DC-DC converter, IXYSDC-DC converterNot recordedIXYS

      Printed LS1 on the part. Easy to misread as L51. 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, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, 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.

    • IXD3236D31C4R-Gprinted LS1DC-DC converter, IXYSDC-DC converterNot recordedIXYS

      Printed LS1 on the part. Easy to misread as L51. 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, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, 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.

    • SS1P5Lprinted 15LSchottky diode, VishaySchottky diodeNot recordedVishay

      Printed 15L on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      Schottky diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Diode: SBR, 50V, 1A, Vf<0.59V(1A)
      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 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

      Dead, it reads

      • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
      • A reading the wrong way round as well: leaky.
      • Open both ways: failed open.
      On the board
      this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

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

    • XC6129N31F7R-Gprinted L5LVoltage supervisor, TorexVoltage supervisorNot recordedTorex

      Printed L5L on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 3.1V±0.8%, -Reset ODO, Rel. Delay, Det. Delay, Undef. Prot.
      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.

    • XC6415AA517R-Gprinted 151LDO regulator, TorexLDO regulatorNot recordedTorex

      Printed 151 on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=4.20/3.10V±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.

    • XC6423AB511R-Gprinted 151LDO regulator, TorexLDO regulatorNot recordedTorex

      Printed 151 on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=3.10/3.10V±1%, 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.

    • XC9236D3LC0R-Gprinted LSLDC-DC converter, TorexDC-DC converterNot recordedTorex

      Printed LSL on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      DC-DC converter
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>1.8V, 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.

    • XC9236D3LC4R-Gprinted LSLDC-DC converter, TorexDC-DC converterNot recordedTorex

      Printed LSL on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      DC-DC converter
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>1.8V, 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.

    • XC9236D31C0R-Gprinted LS1DC-DC converter, TorexDC-DC converterNot recordedTorex

      Printed LS1 on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      DC-DC converter
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, 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.

    • XC9236D31C4R-Gprinted LS1DC-DC converter, TorexDC-DC converterNot recordedTorex

      Printed LS1 on the part. Easy to misread as L51. Check that character with a loupe before you order anything.

      What it is
      DC-DC converter
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, 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.

17 more parts have codes that begin with L51: none in SOT-363, 17 with no package on record

Codes that begin with L51

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

17 parts have no package on record. Nothing rules them out, so they stay.

  • AAT60151A-S14printed 151AVoltage supervisor, Advanced Analog TechnologyVoltage supervisorAdvanced Analog Technology

    Printed 151A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Advanced Analog Technology
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 5.1V±2%, +Reset ODO
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • AAT60151B-S14printed 151BVoltage supervisor, Advanced Analog TechnologyVoltage supervisorAdvanced Analog Technology

    Printed 151B. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Advanced Analog Technology
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 5.1V±2%, +Reset PPO
    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.

  • AAT60151C-S14printed 151CVoltage supervisor, Advanced Analog TechnologyVoltage supervisorAdvanced Analog Technology

    Printed 151C. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Advanced Analog Technology
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 5.1V±2%, -Reset ODO
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • AAT60151D-S14printed 151DVoltage supervisor, Advanced Analog TechnologyVoltage supervisorAdvanced Analog Technology

    Printed 151D. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Advanced Analog Technology
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 5.1V±2%, -Reset PPO
    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.

  • KP15L07printed 15L7ShindengenNot recordedShindengen

    Printed 15L7. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Not recorded
    Maker
    Shindengen
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Thy-SPD: V Of-St=65V, Ifsm=150A(1ms), Ih=100mA, Bidirectional
    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.

  • KP15L08printed 15L8ShindengenNot recordedShindengen

    Printed 15L8. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Not recorded
    Maker
    Shindengen
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Thy-SPD: V Of-St=70V, Ifsm=150A(1ms), Ih=100mA, Bidirectional
    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.

  • LR31515BG-AG6printed 1515GLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1515G. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.5V±0.5%, 150mA, +CE, H-free
    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.

  • LR31515BL-AG6printed 1515LLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1515L. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.5V±0.5%, 150mA, +CE, L-free
    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.

  • LR31516BG-AG6printed 1516GLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1516G. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.6V±0.5%, 150mA, +CE, H-free
    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.

  • LR31516BL-AG6printed 1516LLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1516L. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.6V±0.5%, 150mA, +CE, L-free
    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.

  • LR31517BG-AG6printed 1517GLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1517G. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.7V±0.5%, 150mA, +CE, H-free
    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.

  • LR31517BL-AG6printed 1517LLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1517L. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.7V±0.5%, 150mA, +CE, L-free
    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.

  • LR31518BG-AG6printed 1518GLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1518G. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.8V±0.5%, 150mA, +CE, H-free
    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.

  • LR31518BL-AG6printed 1518LLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1518L. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.8V±0.5%, 150mA, +CE, L-free
    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.

  • LR31519BG-AG6printed 1519GLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1519G. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.9V±0.5%, 150mA, +CE, H-free
    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.

  • LR31519BL-AG6printed 1519LLDO regulator, UnisonicLDO regulatorUnisonic

    Printed 1519L. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    LDO regulator
    Maker
    Unisonic
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/1.9V±0.5%, 150mA, +CE, L-free
    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.

  • SN74LS14printed LS14Logic gate, Texas InstrumentsLogic gateTexas Instruments

    Printed LS14. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Hex Schmitt-Trigger Inverters
    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.

Did you find your part?

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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.

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