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SMD code 1Ds

Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.

The last letter, s, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and 1D was searched.

118 parts are printed 1Ds

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.

  • BC846BWSOT-323Transistor, 3 pins, NXPTransistorSOT-3233 pinsNXP
    What it is
    Transistor
    Maker
    NXP
    Package
    SOT-323
    Pins
    3
    Details
    SMD General Purpose NPN Transistors
    Source
    Published code list

    Is it dead? The meter test is below: Bipolar transistor.

  • BC846USOT-23-66 pins, InfineonNot recordedSOT-23-66 pinsInfineon
    What it is
    Not recorded
    Maker
    Infineon
    Package
    SOT-23-6
    Pins
    6
    Details
    Si-npn: Dual, AF, 80V, 100mA, 250mW, B=110..450, >100MHz
    Source
    Published code list

    Is it dead? The meter test is below: This part.

  • BZX384C56SOD-323Zener diode, 2 pins, Taitron ComponentsZener diodeSOD-3232 pinsTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SOD-323
    Pins
    2
    Source
    An older or alternative marking, from a published code list

    Is it dead? The meter test is below: Zener diode.

  • FDZ56T1GSOD-323Zener diode, 2 pins, First SilionZener diodeSOD-3232 pinsFirst Silion
    What it is
    Zener diode
    Maker
    First Silion
    Package
    SOD-323
    Pins
    2
    Details
    Zener diode: 52..60V, Izt=2mA, Zzt=200, 200mW
    Source
    Published code list

    Is it dead? The meter test is below: Zener diode.

  • FUS1ASMA2 pins, Fagor ElectronicaNot recordedSMA2 pinsFagor Electronica
    What it is
    Not recorded
    Maker
    Fagor Electronica
    Package
    SMA
    Pins
    2
    Details
    Diode: U-fast recov. rectif, 50V, 1.5A, Vf<1V(1A), 50ns
    Source
    Published code list

    Is it dead? The meter test is below: Silicon diode.

  • GS1002FLSOD-123FRectifier, 2 pins, Won-Top ElectronicsRectifierSOD-123F2 pinsWon-Top Electronics
    What it is
    Rectifier
    Maker
    Won-Top Electronics
    Package
    SOD-123F
    Pins
    2
    Details
    Diode: Rectifier, 200V, 1A, Vf<1.1V(1A), 4pF
    Source
    Published code list

    Is it dead? The meter test is below: Silicon diode.

  • GSMM5Z56VSOD-523Zener diode, 2 pins, Good-ArkZener diodeSOD-5232 pinsGood-Ark
    What it is
    Zener diode
    Maker
    Good-Ark
    Package
    SOD-523
    Pins
    2
    Details
    Zener diode: 52..60V, Izt=1mA, Zzt=200, 200mW
    Source
    Published code list

    Is it dead? The meter test is below: Zener diode.

  • IRLML5103SOT-23P-channel MOSFET, 3 pins, InfineonP-channel MOSFETSOT-233 pinsInfineon
    What it is
    P-channel MOSFET
    Maker
    Infineon
    Package
    SOT-23
    Pins
    3
    Details
    -30V Single P-Channel Power MOSFET in a Micro 3 package
    Source
    An older or alternative marking, from a published code list

    Is it dead? The meter test is below: P-channel MOSFET.

  • KST42SOT-233 pins, FairchildNot recordedSOT-233 pinsFairchild
    What it is
    Not recorded
    Maker
    Fairchild
    Package
    SOT-23
    Pins
    3
    Details
    Si-npn: Vid, 300/300V, 500mA, 350mW, B>40, >50MHz
    Source
    Published code list

    Is it dead? The meter test is below: This part.

  • KST42MTFSOT-233 pins, onsemiNot recordedSOT-233 pinsonsemi
    What it is
    Not recorded
    Maker
    onsemi
    Package
    SOT-23
    Pins
    3
    Details
    General purpose NPN Transistor
    Source
    Published code list

    Is it dead? The meter test is below: Bipolar transistor.

  • 5 more parts have no package on record
    • BD46E462G-MVoltage supervisor, ROHMVoltage supervisorNot recordedNot recordedROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 4.6V±1%, -MR, -Reset PPO, Rdt=200ms
      Source
      Published code list

      Is it dead? The meter test is below: Integrated circuit.

    • BU4344FVoltage supervisor, ROHMVoltage supervisorNot recordedNot recordedROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS-IC: Voltage Detector 4,4V, Reset Push-pull output
      Source
      Published code list

      Is it dead? The meter test is below: Integrated circuit.

    • BU4344FWEVoltage supervisor, ROHMVoltage supervisorNot recordedNot recordedROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS-IC: Voltage Detector 4,4V, Reset Push-pull output
      Source
      Published code list

      Is it dead? The meter test is below: Integrated circuit.

    • BU4344GVoltage supervisor, ROHMVoltage supervisorNot recordedNot recordedROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS-IC: Voltage Detector 4,4V, Reset Push-pull output
      Source
      Published code list

      Is it dead? The meter test is below: Integrated circuit.

    • IXD5127N21BNRVoltage supervisor, IXYSVoltage supervisorNot recordedNot recordedIXYS
      What it is
      Voltage supervisor
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.1V±0.8%, -Reset ODO, -MR, 100ms Rt delay
      Source
      Published code list

      Is it dead? The meter test is below: Integrated circuit.

Is it dead? One meter test per kind

Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.

Bipolar transistor

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

Working, it reads

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

Dead, it reads

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

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

This part

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.

Integrated circuit

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.

Zener diode

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.

Silicon diode

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

Working, it reads

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

Dead, it reads

  • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
  • Open both ways: failed open.
  • A reading the wrong way round as well: leaky.
On the board
this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

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

P-channel MOSFET

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.

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