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SMD code search: identify a part by its marking

2 parts in SOD-723 are printed 4C. 28 printed with a similar-looking code.

Not sure which one you have?

Answer up to 4 quick questions and these 30 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • BZT52C17WUSOD-723Zener diode, 2 pins, Taitron ComponentsZener diode2 pinsTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SOD-723
    Pins
    2
    Details
    SMD Zener Diodes (Two Terminals) - 200mW
    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.

  • BZX784C17SOD-723Zener diode, 2 pins, PanjitZener diode2 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-723
    Pins
    2
    Details
    Zener diode: 16.15..17.85V, Zzt=40, Izt=5mA, 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.

  • 28 more parts have no package on record. Nothing rules them out, so they stay.
    • ESD8104MUESD protection diode, onsemiESD protection diodeNot recordedonsemi
      What it is
      ESD protection diode
      Maker
      onsemi
      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.

    • GBLC24CDNESD protection diode, ProTek DevicesESD protection diodeNot recordedProTek Devices
      What it is
      ESD protection diode
      Maker
      ProTek Devices
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Ultra Low Capacitance TVS
      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.

    • NX5P2924CUKLoad switch, NXPLoad switchNot recordedNXP
      What it is
      Load switch
      Maker
      NXP
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Logic controlled high-side power switch
      Source
      Manufacturer datasheet

      Is it dead?

      Voltage, board powered, black probe on ground.

      Working, it reads

      Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.

      Dead, it reads

      • Output at the input voltage while switched off: the pass element has shorted.
      • Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
      On the board:
      An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
      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 pinout and whether the enable is active high or low differ between parts. The datasheet gives both.

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

    • SZESD8104MUESD protection diode, onsemiESD protection diodeNot recordedonsemi
      What it is
      ESD protection diode
      Maker
      onsemi
      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.

    • TSCD034WTSchottky diode, Taitron ComponentsSchottky diodeNot recordedTaitron Components
      What it is
      Schottky diode
      Maker
      Taitron Components
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Low Profile Chip Type Schottky Rectifier
      Source
      Manufacturer datasheet

      Is it dead?

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

      Working, it reads

      About 0.15 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.

    • 3SK269N-channel MOSFET, PanasonicN-channel MOSFETNot recordedPanasonic
      What it is
      N-channel MOSFET
      Maker
      Panasonic
      Package
      Not recorded
      Pins
      Not recorded
      Details
      MOSFET n-type: Dual gate, UHF, LN, 15V, +30mA, 150mW, Idss=4..20mA
      Source
      Published code list

      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 source, black on the drain: 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. A drain short can be the load. 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.

    • 74LVCH2T45RA3Diodes IncorporatedNot recordedNot recordedDiodes Incorporated
      What it is
      Not recorded
      Maker
      Diodes Incorporated
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Dual-bit, dual-supply voltage level translator/transceiver; 3-state
      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.

    • AP7341-15FS4-7RLDO regulator, Diodes IncorporatedLDO regulatorNot recordedDiodes Incorporated
      What it is
      LDO regulator
      Maker
      Diodes Incorporated
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 1.5V±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.

    • CDZ55C4V3TZener diode, Crownpo TechnologyZener diodeNot recordedCrownpo Technology
      What it is
      Zener diode
      Maker
      Crownpo Technology
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 4.09..4.52V, Zzt=80, Izt=5mA, 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.

    • HZU4CLLZener diode, RenesasZener diodeNot recordedRenesas
      What it is
      Zener diode
      Maker
      Renesas
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 4.0..4.4V, Izt=0.5mA, Zzt=370, 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.

    • IXD5126N38ANR-GVoltage supervisor, IXYSVoltage supervisorNot recordedIXYS
      What it is
      Voltage supervisor
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 3.8V±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.

    • IXD5127N19ENRVoltage supervisor, IXYSVoltage supervisorNot recordedIXYS
      What it is
      Voltage supervisor
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 1.9V±0.8%, -Reset ODO, -MR, 800ms Rt delay
      Source
      Published code list

      Is it dead?

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

      Working, it reads

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

      Dead, it reads

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

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

    • R1161D241ANisshinbo Micro DevicesNot recordedNot recordedNisshinbo Micro Devices
      What it is
      Not recorded
      Maker
      Nisshinbo Micro Devices
      Package
      Not recorded
      Pins
      Not recorded
      Details
      VR-IC: LDO, -CE, 2.4V±2%, 350mA
      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.

    • RKZ4C1KDZener diode, RenesasZener diodeNot recordedRenesas
      What it is
      Zener diode
      Maker
      Renesas
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 4.0..4.2V, Izt=5mA, Zzt=100, 500mW
      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.

    • RKZ4C2KDZener diode, RenesasZener diodeNot recordedRenesas
      What it is
      Zener diode
      Maker
      Renesas
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 4.1..4.3V, Izt=5mA, Zzt=100, 500mW
      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.

    • RKZ4C3KDZener diode, RenesasZener diodeNot recordedRenesas
      What it is
      Zener diode
      Maker
      Renesas
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 4.2..4.4V, Izt=5mA, Zzt=100, 500mW
      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.

    • UNRF1A9Digital transistor (PNP, resistors built in), PanasonicDigital transistor (PNP, resistors built in)Not recordedPanasonic
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      Panasonic
      Package
      Not recorded
      Pins
      Not recorded
      Details
      PNP transistor: Sw, 50V, 80mA, 100mW, 80MHz, R1/R2=1k/10k
      Source
      Published code list

      Is it dead?

      Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

      Working, it reads

      Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

      Dead, it reads

      • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
      • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
      • Base to emitter near 0 Ω: failed short.
      On the board
      this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
      Watch for:
      On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

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

    • USCD034ZowieNot recordedNot recordedZowie
      What it is
      Not recorded
      Maker
      Zowie
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Si-diode: Schottky Barrier Rectifier, 40V, 0,3A, Vf<0,5V(0,3A)
      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.

    • XC6126N38ANR-GVoltage supervisor, TorexVoltage supervisorNot recordedTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 3.8V±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.

    • XC6127N19ENRVoltage supervisor, TorexVoltage supervisorNot recordedTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 1.9V±0.8%, -Reset ODO, -MR, Rdt=800ms
      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.

    • XC6129C19E9R-GVoltage supervisor, TorexVoltage supervisorNot recordedTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 1.9V±0.8%, -Reset PPO, Releas. Delay, Det. Delay
      Source
      Published code list

      Is it dead?

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

      Working, it reads

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

      Dead, it reads

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

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

    • XC6129C19ENR-GVoltage supervisor, TorexVoltage supervisorNot recordedTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 1.9V±0.8%, -Reset PPO, Releas. Delay, Det. Delay
      Source
      Published code list

      Is it dead?

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

      Working, it reads

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

      Dead, it reads

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

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

    • XC6129N19E9R-GVoltage supervisor, TorexVoltage supervisorNot recordedTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 1.9V±0.8%, -Reset ODO, Releas. Delay, Det. Delay
      Source
      Published code list

      Is it dead?

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

      Working, it reads

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

      Dead, it reads

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

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

    • XC6129N19ENR-GVoltage supervisor, TorexVoltage supervisorNot recordedTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 1.9V±0.8%, -Reset ODO, Releas. Delay, Det. Delay
      Source
      Published code list

      Is it dead?

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

      Working, it reads

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

      Dead, it reads

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

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

    • XC6213B42ANRLDO regulator, TorexLDO regulatorNot recordedTorex
      What it is
      LDO regulator
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      VR-IC: LDO, CE, 4.25V±2%, 150mA
      Source
      Published code list

      Is it dead?

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

      Working, it reads

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

      Dead, it reads

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

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

    • XC6221D201NRLDO regulator, TorexLDO regulatorNot recordedTorex
      What it is
      LDO regulator
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 2.0V±1%, 200mA, +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.

    • XC6221D2017RLDO regulator, TorexLDO regulatorNot recordedTorex
      What it is
      LDO regulator
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 2.0V±1%, 200mA, +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.

    • XC6223E2219R-GLDO regulator, TorexLDO regulatorNot recordedTorex
      What it is
      LDO regulator
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 2.2V±1%, 300mA, +CE, ICP
      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.

28 more parts are printed with a code easy to misread as 4C: none in SOD-723, 28 with no package on record

Printed with a code easy to misread

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

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

  • BFCN-7900+printed 46RF filter, Mini-CircuitsRF filterNot recordedMini-Circuits

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    RF filter
    Maker
    Mini-Circuits
    Package
    Not recorded
    Pins
    Not recorded
    Details
    LTCC filter, 7800-8100 MHz
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range and ohms range, part lifted.

    Working, it reads

    Depends on what it is. The datasheet, or an identical part, says.

    Dead, it reads

    • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
    • Open between every pair of pins: failed open, or a part that reads open when working.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.

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

  • EMB32A03VAprinted 46Dual N-channel MOSFET, Excelliance MOSDual N-channel MOSFETNot recordedExcelliance MOS

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Dual N-channel MOSFET
    Maker
    Excelliance MOS
    Package
    Not recorded
    Pins
    Not recorded
    Details
    30 V, 5.5 A dual N-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. Test each MOSFET on its own pins, as the datasheet's pinout gives them.

    Working, it reads

    Red probe on the source, black on the drain: 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. A drain short can be the load. 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.

  • ESD8504GMUprinted 4GESD protection diode, onsemiESD protection diodeNot recordedonsemi

    Printed 4G on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    onsemi
    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.

  • SGM2038-3.3XUDY4Gprinted 46LDO regulator, 4 pins, SG MicroLDO regulator4 pinsSG Micro

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    Not recorded
    Pins
    4
    Details
    3.3 V output, 500mA, Low Noise, Very Low Dropout Bias Rail CMOS 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.

  • SGM2045LC-0.8XXDH4Gprinted 46LDO regulator, 4 pins, SG MicroLDO regulator4 pinsSG Micro

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    SG Micro
    Package
    Not recorded
    Pins
    4
    Details
    0.8 V output, 300mA, Low VIN, Ultra-Low Noise, Start-Up Current, High PSRR 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.

  • ADP150ACBZ-2.8-R7printed 46LDO regulator, 4 pins, Analog DevicesLDO regulator4 pinsAnalog Devices

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Analog Devices
    Package
    Not recorded
    Pins
    4
    Details
    Linear voltage regulator IC: LDO, 2.8V±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.

  • AP7341-25FS4-7Rprinted 4GLDO regulator, Diodes IncorporatedLDO regulatorNot recordedDiodes Incorporated

    Printed 4G on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Diodes Incorporated
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, 2.5V±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.

  • AP8822N-16GIprinted 46Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Anwell Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 1.6V±2%, -Reset ODO, 200ms Rt delay, H-free
    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.

  • AP8822N-16GSprinted 46Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Anwell Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 1.6V±2%, -Reset ODO, 200ms Rt delay, H-free
    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.

  • AP8822N-16PIprinted 46Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Anwell Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 1.6V±2%, -Reset ODO, 200ms Rt delay
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • AP8822N-16PSprinted 46Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    Anwell Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 1.6V±2%, -Reset ODO, 200ms Rt delay
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • CDZ55C4V7Tprinted 4GZener diode, Crownpo TechnologyZener diodeNot recordedCrownpo Technology

    Printed 4G on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Zener diode
    Maker
    Crownpo Technology
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Zener diode: 4.47..4.94V, Zzt=70, Izt=5mA, 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.

  • EC95810N16C7Iprinted 46Voltage supervisor, E-CMOSVoltage supervisorNot recordedE-CMOS

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    E-CMOS
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 1.6V±2%, -Reset ODO, Td=200ms
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • EC95810N16C7Sprinted 46Voltage supervisor, E-CMOSVoltage supervisorNot recordedE-CMOS

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Voltage supervisor
    Maker
    E-CMOS
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 1.6V±2%, -Reset ODO, Td=200ms
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • IXD5126N32ANR-Gprinted 46Voltage supervisor, IXYSVoltage supervisorNot recordedIXYS

    Printed 46 on the part. Easy to misread as 4C. 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: 3.2V±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.

  • MIC5380-1.8/1.2YFTprinted 4GLDO regulator, MicrelLDO regulatorNot recordedMicrel

    Printed 4G on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Micrel
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, Dual out, Vo1/Vo2=1.8V/1.2V±2%, 150mA, +CE
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

  • PDTA114TEFprinted 463 pins, NexperiaNot recorded3 pinsNexperia

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Nexperia
    Package
    Not recorded
    Pins
    3
    Details
    equivalent PDTA114TS
    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.

  • R1161D241Bprinted 4GNisshinbo Micro DevicesNot recordedNot recordedNisshinbo Micro Devices

    Printed 4G on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Nisshinbo Micro Devices
    Package
    Not recorded
    Pins
    Not recorded
    Details
    VR-IC: LDO, CE, 2.4V±2%, 350mA
    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.

  • XC6126N32ANR-Gprinted 46Voltage supervisor, TorexVoltage supervisorNot recordedTorex

    Printed 46 on the part. Easy to misread as 4C. 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: 3.2V±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.

  • XC6213B462NRprinted 46LDO regulator, TorexLDO regulatorNot recordedTorex

    Printed 46 on the part. Easy to misread as 4C. Check that character with a loupe before you order anything.

    What it is
    LDO regulator
    Maker
    Torex
    Package
    Not recorded
    Pins
    Not recorded
    Details
    VR-IC: LDO, CE, 4.6V±2%, 150mA
    Source
    Published code list

    Is it dead?

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

    Working, it reads

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

    Dead, it reads

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

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

8 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.

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.

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