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SMD code search: identify a part by its marking

1 part is printed 0OI. 94 printed with a similar-looking code.

Not sure which one you have?

Answer up to 4 quick questions and these 50 parts are ranked, with a meter test that settles it. It works on a dead part too.

The only part printed 0OI in our tables

SGM2078-2.9XN5G

What it is
LDO regulator
Maker
SG Micro
Package
SOT-23-5
Pins
5
Details
2.9 V output, 300mA, 1.2V Logic, Low Power and Low Dropout RF 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.

Datasheetfor SGM2078-2.9XN5G, opens in a new tab

Was it this one?

Printed with a code easy to misread

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

  • AZ23B2V7printed DD1SOT-23Zener diode, 3 pins, VishayZener diodeSOT-233 pinsVishay

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOT-23
    Pins
    3
    Details
    2.7 V Zener diode
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board
    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.

  • AZ23B2V7-Gprinted DD1SOT-23Zener diode, 3 pins, VishayZener diodeSOT-233 pinsVishay

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOT-23
    Pins
    3
    Details
    2.7 V Zener diode
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board
    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.

  • MMFTP245Kprinted DQ1SOT-23MOSFET, 3 pins, DiotecMOSFETSOT-233 pinsDiotec

    Printed DQ1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    MOSFET
    Maker
    Diotec
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted.
    • No body diode at all: failed open.
    On the board
    the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

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

  • SGM2053S-1.8XN5Gprinted 0DISOT-23-5LDO regulator, 5 pins, SG MicroLDO regulatorSOT-23-55 pinsSG Micro

    Printed 0DI on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-23-5
    Pins
    5
    Details
    1.8 V output, 500mA, Ultra-Low Dropout, Low Power, RF 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.

  • SGM2078-1.1XC5Gprinted 0OLSOT-353LDO regulator, 5 pins, SG MicroLDO regulatorSOT-3535 pinsSG Micro

    Printed 0OL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-353
    Pins
    5
    Details
    1.1 V output, 300mA, 1.2V Logic, Low Power and Low Dropout RF 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.

  • SGM2220-1.5XK3Gprinted 0O1SOT-89LDO regulator, 3 pins, SG MicroLDO regulatorSOT-893 pinsSG Micro

    Printed 0O1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-89
    Pins
    3
    Details
    1.5 V output, 300mA, 0.9μA Low Quiescent Current, Low Dropout and High 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.

  • SGM2220-3.3XN5Gprinted 00LSOT-23-5LDO regulator, 5 pins, SG MicroLDO regulatorSOT-23-55 pinsSG Micro

    Printed 00L on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-23-5
    Pins
    5
    Details
    3.3 V output, 300mA, 0.9μA Low Quiescent Current, Low Dropout and High 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.

  • SGM2221-3.3XN5Gprinted 00ISOT-23-5LDO regulator, 5 pins, SG MicroLDO regulatorSOT-23-55 pinsSG Micro

    Printed 00I on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    SOT-23-5
    Pins
    5
    Details
    3.3 V output, 300mA, 0.9μA Low Quiescent Current, Low Dropout and High 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.

  • SGM48535BXN6Gprinted 001SOT-23-66 pins, SG MicroNot recordedSOT-23-66 pinsSG Micro

    Printed 001 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    SG Micro
    Package
    SOT-23-6
    Pins
    6
    Details
    SGM48534A/SGM48534B Low-Side Gate Drivers Response Over-Current Protection
    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.

  • SM2601PSCprinted D01SOT-23-6P-channel MOSFET, 6 pins, Sinopower SemiconductorP-channel MOSFETSOT-23-66 pinsSinopower Semiconductor

    Printed D01 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    P-channel MOSFET
    Maker
    Sinopower Semiconductor
    Package
    SOT-23-6
    Pins
    6
    Details
    20 V, 7.3 A P-channel MOSFET
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
    • No body diode at all: failed open.
    On the board
    the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

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

  • VESD01A2-03G-G3printed D01SOT-323ESD protection diode, 3 pins, VishayESD protection diodeSOT-3233 pinsVishay

    Printed D01 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Vishay
    Package
    SOT-323
    Pins
    3
    Details
    Dual-Line ESD-Protection Diode Array in SOT-323
    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.

  • AD5170BRM100printed DD1MSOP-1010 pins, Analog DevicesNot recordedMSOP-1010 pinsAnalog Devices

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Analog Devices
    Package
    MSOP-10
    Pins
    10
    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.

  • AD5243BRM2.5printed D0LMSOP-1010 pins, Analog DevicesNot recordedMSOP-1010 pinsAnalog Devices

    Printed D0L on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Analog Devices
    Package
    MSOP-10
    Pins
    10
    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.

  • AZ23C2V7printed DD1SOT-23Zener diode, 3 pins, Diodes IncorporatedZener diodeSOT-233 pinsDiodes Incorporated

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Diodes Incorporated
    Package
    SOT-23
    Pins
    3
    Details
    2.7V, 300mW, Surface Mount Zener Diodes
    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.

  • AZ23C13printed DDISOT-23Zener diode, 3 pins, Diodes IncorporatedZener diodeSOT-233 pinsDiodes Incorporated

    Printed DDI on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Diodes Incorporated
    Package
    SOT-23
    Pins
    3
    Details
    13V, 300mW, Surface Mount Zener Diodes
    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.

  • AZ23C18printed DDLSOT-23Zener diode, 3 pins, Diodes IncorporatedZener diodeSOT-233 pinsDiodes Incorporated

    Printed DDL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Diodes Incorporated
    Package
    SOT-23
    Pins
    3
    Details
    18V, 300mW, Surface Mount Zener Diodes
    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.

  • ELM85211Aprinted 00LSOT-89LDO regulator, 3 pins, ELM TechnologyLDO regulatorSOT-893 pinsELM Technology

    Printed 00L on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    ELM Technology
    Package
    SOT-89
    Pins
    3
    Details
    Linear voltage regulator IC: LDO, 2.1V±2%, 600mA
    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.

  • HE61CC3001MRprinted D01SOT-23Voltage supervisor, 3 pins, Heermicr SemicconductorVoltage supervisorSOT-233 pinsHeermicr Semicconductor

    Printed D01 on the part. Easy to misread as 0OI. 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: 3.0V±1%, +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.

  • HE7030MCM5R1printed D01SOT-23-5Voltage supervisor, 5 pins, Heermicr SemicconductorVoltage supervisorSOT-23-55 pinsHeermicr Semicconductor

    Printed D01 on the part. Easy to misread as 0OI. 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: 3.0V±1%, +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.

  • HE7030MCNR1printed D01SOT-23Voltage supervisor, 3 pins, Heermicr SemicconductorVoltage supervisorSOT-233 pinsHeermicr Semicconductor

    Printed D01 on the part. Easy to misread as 0OI. 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: 3.0V±1%, +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.

  • HE7030MCPR1printed D01SOT-89Voltage supervisor, 3 pins, Heermicr SemicconductorVoltage supervisorSOT-893 pinsHeermicr Semicconductor

    Printed D01 on the part. Easy to misread as 0OI. 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: 3.0V±1%, +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.

  • HM6210D322MRprinted 0D1SOT-23-5LDO regulator, 5 pins, Huamei SemiconductorLDO regulatorSOT-23-55 pinsHuamei Semiconductor

    Printed 0D1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Huamei Semiconductor
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 3.2V±2%, 700mA, -CE, CL
    Source
    Published code list

    Is it dead?

    Voltage, board powered, black probe on ground. Then ohms with the power off.

    Working, it reads

    Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

    Dead, it reads

    • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
    • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
    • Power off, input to output near 0 Ω: shorted.
    On the board:
    An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
    Compare:
    The same regulator on another rail or another board shows the right voltages and the right resistances.
    Watch for:
    Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

  • HM6210D322PRprinted 0D1SOT-89-5LDO regulator, 5 pins, Huamei SemiconductorLDO regulatorSOT-89-55 pinsHuamei Semiconductor

    Printed 0D1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Huamei Semiconductor
    Package
    SOT-89-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 3.2V±2%, 700mA, -CE, CL
    Source
    Published code list

    Is it dead?

    Voltage, board powered, black probe on ground. Then ohms with the power off.

    Working, it reads

    Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

    Dead, it reads

    • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
    • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
    • Power off, input to output near 0 Ω: shorted.
    On the board:
    An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
    Compare:
    The same regulator on another rail or another board shows the right voltages and the right resistances.
    Watch for:
    Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

  • HM6210D492MRprinted 0DLSOT-23-5LDO regulator, 5 pins, Huamei SemiconductorLDO regulatorSOT-23-55 pinsHuamei Semiconductor

    Printed 0DL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Huamei Semiconductor
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 4.9V±2%, 700mA, -CE, CL
    Source
    Published code list

    Is it dead?

    Voltage, board powered, black probe on ground. Then ohms with the power off.

    Working, it reads

    Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

    Dead, it reads

    • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
    • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
    • Power off, input to output near 0 Ω: shorted.
    On the board:
    An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
    Compare:
    The same regulator on another rail or another board shows the right voltages and the right resistances.
    Watch for:
    Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

  • HM6210D492PRprinted 0DLSOT-89-5LDO regulator, 5 pins, Huamei SemiconductorLDO regulatorSOT-89-55 pinsHuamei Semiconductor

    Printed 0DL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Huamei Semiconductor
    Package
    SOT-89-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 4.9V±2%, 700mA, -CE, CL
    Source
    Published code list

    Is it dead?

    Voltage, board powered, black probe on ground. Then ohms with the power off.

    Working, it reads

    Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

    Dead, it reads

    • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
    • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
    • Power off, input to output near 0 Ω: shorted.
    On the board:
    An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
    Compare:
    The same regulator on another rail or another board shows the right voltages and the right resistances.
    Watch for:
    Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

  • IXD3236B3LCER-Gprinted DDLUSP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS

    Printed DDL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    IXYS
    Package
    USP-6C
    Pins
    6
    Details
    DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>2V, HSST, 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.

  • IXD3236B3LCMR-Gprinted DDLSOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS

    Printed DDL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    IXYS
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>2V, HSST, 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.

  • IXD3236B31CER-Gprinted DD1USP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    IXYS
    Package
    USP-6C
    Pins
    6
    Details
    DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>2V, HSST, 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.

  • IXD3236B31CMR-Gprinted DD1SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    DC-DC converter
    Maker
    IXYS
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>2V, HSST, 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.

  • LN6210D322Mprinted 0D1SOT-23-5LDO regulator, 5 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-23-55 pinsShanghai Natlinear Electronics

    Printed 0D1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 3.2V±2%, 700mA, -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.

  • LN6210D322Pprinted 0D1SOT-89-5LDO regulator, 5 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-89-55 pinsShanghai Natlinear Electronics

    Printed 0D1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-89-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 3.2V±2%, 700mA, -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.

  • LN6210D492Mprinted 0DLSOT-23-5LDO regulator, 5 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-23-55 pinsShanghai Natlinear Electronics

    Printed 0DL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 4.9V±2%, 700mA, -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.

  • LN6210D492Pprinted 0DLSOT-89-5LDO regulator, 5 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-89-55 pinsShanghai Natlinear Electronics

    Printed 0DL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Shanghai Natlinear Electronics
    Package
    SOT-89-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 4.9V±2%, 700mA, -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.

  • R3116N171Aprinted D0LSOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh

    Printed D0L on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Ricoh
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 1.7V±0.8%, -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.

  • R3120N114Aprinted DD1SOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh

    Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Ricoh
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 11.4V±1.5%, -Reset ODO
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • RP173N121A5printed D01SOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh

    Printed D01 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Ricoh
    Package
    SOT-23-5
    Pins
    5
    Details
    Linear voltage regulator IC: LDO, 1.25V±1%, 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.

  • S-8322AIMP-DOIprinted DOISOT-23-55 pins, ABLICNot recordedSOT-23-55 pinsABLIC

    Printed DOI on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    ABLIC
    Package
    SOT-23-5
    Pins
    5
    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.

  • 12 more parts have no package on record
    • S-8242BBI-I8T1printed QOIBattery protection IC, ABLICBattery protection ICNot recordedNot recordedABLIC

      Printed QOI on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      Battery protection IC
      Maker
      ABLIC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK
      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.

    • SMV2202-040LFprinted DD1Varicap diode, SkyworksVaricap diodeNot recordedNot recordedSkyworks

      Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      Varicap diode
      Maker
      Skyworks
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Hyperabrupt Tuning Varactor Diodes
      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 0.6 to 0.9 V anode to cathode, 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.
      • 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 varicap that has drifted in capacitance reads normal on a meter. Only a capacitance meter or the tuning itself shows it.

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

    • TLV70028DDCprinted ODLLDO regulator, 5 pins, Texas InstrumentsLDO regulatorNot recorded5 pinsTexas Instruments

      Printed ODL on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      Texas Instruments
      Package
      Not recorded
      Pins
      5
      Details
      200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
      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.

    • AD5243printed D0L10 pins, Analog DevicesNot recordedNot recorded10 pinsAnalog Devices

      Printed D0L on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      Not recorded
      Maker
      Analog Devices
      Package
      Not recorded
      Pins
      10
      Details
      Dual 256-Position I2C Compatible Digital Potentiometer
      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.

    • AD8342ACPZ-WPprinted Q0116 pins, Analog DevicesNot recordedNot recorded16 pinsAnalog Devices

      Printed Q01 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      Not recorded
      Maker
      Analog Devices
      Package
      Not recorded
      Pins
      16
      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.

    • IXD3236B3LC0R-Gprinted DDLDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed DDL on the part. Easy to misread as 0OI. 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, HSST, 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.

    • IXD3236B3LC4R-Gprinted DDLDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed DDL on the part. Easy to misread as 0OI. 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, HSST, 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.

    • IXD3236B31C0R-Gprinted DD1DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed DD1 on the part. Easy to misread as 0OI. 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>2V, HSST, 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.

    • IXD3236B31C4R-Gprinted DD1DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS

      Printed DD1 on the part. Easy to misread as 0OI. 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>2V, HSST, 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.

    • IXD5120C412NR-Gprinted DD1Voltage supervisor, IXYSVoltage supervisorNot recordedNot recordedIXYS

      Printed DD1 on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      Voltage supervisor
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 4.1V±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.

    • S-1711A152J-I6T1printed QQI6 pins, ABLICNot recordedNot recorded6 pinsABLIC

      Printed QQI on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      Not recorded
      Maker
      ABLIC
      Package
      Not recorded
      Pins
      6
      Details
      equivalent [1.5/2.85V Dual LDO]
      Source
      Published code list

      Is it dead?

      Voltage, board powered, black probe on ground. Then ohms with the power off.

      Working, it reads

      Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

      Dead, it reads

      • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
      • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
      • Power off, input to output near 0 Ω: shorted.
      On the board:
      An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
      Compare:
      The same regulator on another rail or another board shows the right voltages and the right resistances.
      Watch for:
      Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

    • S-1711A152J-I6T1xprinted QQILDO regulator, Seiko InstrumentsLDO regulatorNot recordedNot recordedSeiko Instruments

      Printed QQI on the part. Easy to misread as 0OI. Check that character with a loupe before you order anything.

      What it is
      LDO regulator
      Maker
      Seiko Instruments
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/2.85V±1.0%, 150mA, +CE, CL, PDR
      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.

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

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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.

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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.

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