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SMD code 3Ms

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 3M was searched.

69 parts are printed 3Ms

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.

  • BC858ASOT-23PNP transistor, 3 pins, Taitron ComponentsPNP transistorSOT-233 pinsTaitron Components
    What it is
    PNP transistor
    Maker
    Taitron Components
    Package
    SOT-23
    Pins
    3
    Details
    -30 V PNP small-signal transistor, gain group A
    Source
    Manufacturer datasheet

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

  • BC858BSOT-23PNP transistor, 3 pins, Taitron ComponentsPNP transistorSOT-233 pinsTaitron Components
    What it is
    PNP transistor
    Maker
    Taitron Components
    Package
    SOT-23
    Pins
    3
    Details
    -30 V PNP small-signal transistor, gain group B
    Source
    Manufacturer datasheet

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

  • BC858CSOT-23PNP transistor, 3 pins, Taitron ComponentsPNP transistorSOT-233 pinsTaitron Components
    What it is
    PNP transistor
    Maker
    Taitron Components
    Package
    SOT-23
    Pins
    3
    Details
    -30 V PNP small-signal transistor, gain group C
    Source
    Manufacturer datasheet

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

  • BCM856SSOT-363Transistor, 6 pins, InfineonTransistorSOT-3636 pinsInfineon
    What it is
    Transistor
    Maker
    Infineon
    Package
    SOT-363
    Pins
    6
    Source
    Manufacturer datasheet

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

  • BCV62SOT-143Dual PNP transistor, 4 pins, NexperiaDual PNP transistorSOT-1434 pinsNexperia
    What it is
    Dual PNP transistor
    Maker
    Nexperia
    Package
    SOT-143
    Pins
    4
    Details
    PNP current-mirror double transistor
    Source
    Manufacturer datasheet

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

  • CH715WGPSOT-416Schottky diode, 3 pins, ChenmkoSchottky diodeSOT-4163 pinsChenmko
    What it is
    Schottky diode
    Maker
    Chenmko
    Package
    SOT-416
    Pins
    3
    Details
    SCHOTTKY BARRIER DIODE, 40 V, 0.03 A
    Source
    Manufacturer datasheet

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

  • ESD3Z5.0CSOD-323ESD protection diode, 2 pins, YFWESD protection diodeSOD-3232 pinsYFW
    What it is
    ESD protection diode
    Maker
    YFW
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • LESD3Z5.0CMT1GSOD-323ESD protection diode, 2 pins, LRCESD protection diodeSOD-3232 pinsLRC
    What it is
    ESD protection diode
    Maker
    LRC
    Package
    SOD-323
    Pins
    2
    Details
    ESD protection diode, VRWM 5 V, IR @VRWM 1 μA, VBR Min 5.6 V
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • LL052AT523SOT-523ESD protection diode, 3 pins, Formosa MicrosemiESD protection diodeSOT-5233 pinsFormosa Microsemi
    What it is
    ESD protection diode
    Maker
    Formosa Microsemi
    Package
    SOT-523
    Pins
    3
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • S-LESD3Z5.0CMT1GSOD-323ESD protection diode, 2 pins, LRCESD protection diodeSOD-3232 pinsLRC
    What it is
    ESD protection diode
    Maker
    LRC
    Package
    SOD-323
    Pins
    2
    Details
    ESD protection diode, VRWM 5 V, IR @VRWM 1 μA, VBR Min 5.6 V
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • SD5.0CSOD-323ESD protection diode, 2 pins, YFWESD protection diodeSOD-3232 pinsYFW
    What it is
    ESD protection diode
    Maker
    YFW
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • SD05CSOD-323ESD protection diode, 2 pins, LeiditechESD protection diodeSOD-3232 pinsLeiditech
    What it is
    ESD protection diode
    Maker
    Leiditech
    Package
    SOD-323
    Pins
    2
    Details
    5V, 350W, Surface Mount TVS
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • SDK05C-CSOD-323ESD protection diode, 2 pins, SeCoSESD protection diodeSOD-3232 pinsSeCoS
    What it is
    ESD protection diode
    Maker
    SeCoS
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • 2SC3829SOT-233 pins, PanNot recordedSOT-233 pinsPan
    What it is
    Not recorded
    Maker
    Pan
    Package
    SOT-23
    Pins
    3
    Details
    Si-npn: UHF, 15V, 80mA, 200mW, B=50..300, 6GHz
    Source
    Published code list

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

  • 1 more part has no package on record

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.

PNP transistor

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

Working, it reads

Black probe on the base 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.

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.

PNP transistor pair

Diode range, part lifted. Test each transistor on its own pins, as the datasheet's pinout gives them.

Working, it reads

Black probe on the base 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.

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.

TVS or ESD protection diode

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.

Voltage regulator

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.

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.

Printed with a code easy to misread as 3Ms

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 3Ms

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 210 more parts.

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