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SMD code S4

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.

13 parts are printed S4

Not sure which one you have?

Answer up to 4 quick questions and these 13 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • 1PS76SB40SOD-323Schottky diode, 2 pins, Nexperia
    What it is
    Schottky diode
    Maker
    Nexperia
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • 1SS355SOD-323Switching diode, 2 pins, Taiwan Semiconductor
    What it is
    Switching diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-323
    Pins
    2
    Details
    Switching diode, 80 V, 100 mA
    Source
    From the manufacturer's datasheet

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

  • 1SS389SOD-523Schottky diode, 2 pins, JSCJ
    What it is
    Schottky diode
    Maker
    JSCJ
    Package
    SOD-523
    Pins
    2
    Details
    Schottky diode, 10 V, 0.1 A
    Source
    From the manufacturer's datasheet

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

  • BAV70MSOT-883Switching diode, 3 pins, Nexperia
    What it is
    Switching diode
    Maker
    Nexperia
    Package
    SOT-883
    Pins
    3
    Details
    High-speed switching diode, dual common cathode, leadless
    Source
    From the manufacturer's datasheet

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

  • BZX84-B3V9SOT-23Zener diode, 3 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOT-23
    Pins
    3
    Pinout
    • 1 anode
    • 2 not connected
    • 3 cathode
    Details
    3.9 V ±2% voltage regulator (Zener) diode
    Source
    From the manufacturer's datasheet

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

  • CJ2304SOT-23N-channel MOSFET, 3 pins, JSCJ
    What it is
    N-channel MOSFET
    Maker
    JSCJ
    Package
    SOT-23
    Pins
    3
    Details
    MOSFET, N-channel, 30 V, 3.3 A
    Source
    From the manufacturer's datasheet

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

  • SD103AWSOD-123Schottky diode, 2 pins, Taiwan Semiconductor
    What it is
    Schottky diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • SD103AWGWSOD-123Schottky diode, 2 pins, Diotec
    What it is
    Schottky diode
    Maker
    Diotec
    Package
    SOD-123
    Pins
    2
    Details
    SMD Small Signal Schottky Diodes
    Source
    From the manufacturer's datasheet

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

  • SD103AWHSOD-123Schottky diode, 2 pins, Taiwan Semiconductor
    What it is
    Schottky diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • SD103AXSOD-523Schottky diode, 2 pins, JSCJ
    What it is
    Schottky diode
    Maker
    JSCJ
    Package
    SOD-523
    Pins
    2
    Details
    Schottky diode, 40 V, 0.35 A
    Source
    From the manufacturer's datasheet

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

  • SN74LVC1G17DPWX2SONLogic gate, 5 pins, Texas Instruments
    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    X2SON
    Pins
    5
    Details
    Single Schmitt-Trigger Buffer
    Source
    From the manufacturer's datasheet

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

  • ZHCS350WTSOD-523Schottky diode, 2 pins, Diotec
    What it is
    Schottky diode
    Maker
    Diotec
    Package
    SOD-523
    Pins
    2
    Details
    SMD Low Barrier Schottky Rectifier Diodes
    Source
    From the manufacturer's datasheet

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

  • 1 more part has no package on record
    • SD103AXM5Schottky diode, Taiwan Semiconductor
      What it is
      Schottky diode
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

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

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.

Schottky diode

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.

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.

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.

N-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 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.

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.

Printed with a code easy to misread as S4

One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.

Codes that begin with S4

For a marking with its end worn or burnt off. Each code has a page of its own.

Codes not listed here are printed on 11 more parts.

Open this in the search to correct a character or try another package.