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SMD code S2

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.

7 parts are printed S2

Not sure which one you have?

Answer up to 4 quick questions and these 7 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • 1N4448WSSOD-323Switching diode, 2 pins, Taiwan Semiconductor
    What it is
    Switching diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-323
    Pins
    2
    Details
    Switching diode, 75 V, 250 mA
    Source
    From the manufacturer's datasheet

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

    Datasheetfor 1N4448WS, opens in a new tab
  • 1PS76SB70SOD-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.

    Datasheetfor 1PS76SB70, opens in a new tab
  • BAS16LSOD-882Switching diode, 2 pins, Nexperia
    What it is
    Switching diode
    Maker
    Nexperia
    Package
    SOD-882
    Pins
    2
    Details
    High-speed switching diode, single, leadless
    Source
    From the manufacturer's datasheet

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

    Datasheetfor BAS16L, opens in a new tab
  • BZX84-B3V3SOT-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
    3.3 V ±2% voltage regulator (Zener) diode
    Source
    From the manufacturer's datasheet

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

    Datasheetfor BZX84-B3V3, opens in a new tab
  • CJ2302SOT-23N-channel MOSFET, 3 pins, JSCJ
    What it is
    N-channel MOSFET
    Maker
    JSCJ
    Package
    SOT-23
    Pins
    3
    Details
    MOSFET, N-channel, 20 V, 2.1 A
    Source
    From the manufacturer's datasheet

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

    Datasheetfor CJ2302, opens in a new tab
  • SD101BWSOD-123Schottky diode, 2 pins, JSCJ
    What it is
    Schottky diode
    Maker
    JSCJ
    Package
    SOD-123
    Pins
    2
    Details
    Schottky diode, 50 V, 0.015 A
    Source
    From the manufacturer's datasheet

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

    Datasheetfor SD101BW, opens in a new tab
  • SD101BWSSOD-323Schottky diode, 2 pins, JSCJ
    What it is
    Schottky diode
    Maker
    JSCJ
    Package
    SOD-323
    Pins
    2
    Details
    Schottky diode, 50 V
    Source
    From the manufacturer's datasheet

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

    Datasheetfor SD101BWS, opens in a new tab

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.

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.

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.

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.

Printed with a code easy to misread as S2

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 S2

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

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