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SMD code RKs

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 RK was searched.

108 parts are printed RKs

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.

  • 2N7002ESOT-23MOSFET, 3 pins, Formosa MicrosemiMOSFETSOT-233 pinsFormosa Microsemi
    What it is
    MOSFET
    Maker
    Formosa Microsemi
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer datasheet

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

  • 2N7002HWSOT-323N-channel MOSFET, 3 pins, Galaxy MicroelectronicsN-channel MOSFETSOT-3233 pinsGalaxy Microelectronics
    What it is
    N-channel MOSFET
    Maker
    Galaxy Microelectronics
    Package
    SOT-323
    Pins
    3
    Details
    60V, N Channel, Small Signal MOSFETs
    Source
    Manufacturer datasheet

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

  • 2N7002KM-P2-HFSOT-723N-channel MOSFET, 3 pins, ComchipN-channel MOSFETSOT-7233 pinsComchip
    What it is
    N-channel MOSFET
    Maker
    Comchip
    Package
    SOT-723
    Pins
    3
    Details
    60 V, 0.34 A N-channel MOSFET
    Source
    Manufacturer datasheet

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

  • 824500601SMATVS diode, 2 pins, Würth ElektronikTVS diodeSMA2 pinsWürth Elektronik
    What it is
    TVS diode
    Maker
    Würth Elektronik
    Package
    SMA
    Pins
    2
    Details
    WE-TVSP Power TVS Diode SMAJ60A
    Source
    Manufacturer datasheet

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

  • A2N7002HW-HFSOT-323N-channel MOSFET, 3 pins, ComchipN-channel MOSFETSOT-3233 pinsComchip
    What it is
    N-channel MOSFET
    Maker
    Comchip
    Package
    SOT-323
    Pins
    3
    Details
    60 V, 0.3 A N-channel MOSFET
    Source
    Manufacturer datasheet

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

  • ASMAJ60A-HFSMATVS diode, 2 pins, ComchipTVS diodeSMA2 pinsComchip
    What it is
    TVS diode
    Maker
    Comchip
    Package
    SMA
    Pins
    2
    Details
    60 V 400 W unidirectional TVS diode
    Source
    Manufacturer datasheet

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

  • ATV04A600J-HFSMATVS diode, 2 pins, ComchipTVS diodeSMA2 pinsComchip
    What it is
    TVS diode
    Maker
    Comchip
    Package
    SMA
    Pins
    2
    Details
    60 V 400 W unidirectional TVS diode
    Source
    Manufacturer datasheet

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

  • CHT847BWGPSOT-323NPN transistor, 3 pins, ChenmkoNPN transistorSOT-3233 pinsChenmko
    What it is
    NPN transistor
    Maker
    Chenmko
    Package
    SOT-323
    Pins
    3
    Details
    NPN General Purpose Transistor, 45 V, 0.1 A
    Source
    Manufacturer datasheet

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

  • F4TVS60ASOD-123FTVS diode, 2 pins, Good-ArkTVS diodeSOD-123F2 pinsGood-Ark
    What it is
    TVS diode
    Maker
    Good-Ark
    Package
    SOD-123F
    Pins
    2
    Details
    TVS diode, 400 W
    Source
    Manufacturer datasheet

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

  • FMBTRA101SSSOT-23Digital transistor (PNP, resistors built in), 3 pins, Formosa MicrosemiDigital transistor (PNP, resistors built in)SOT-233 pinsFormosa Microsemi
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Formosa Microsemi
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer datasheet

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

  • GSFW0600SOT-883N-channel MOSFET, 3 pins, Good-ArkN-channel MOSFETSOT-8833 pinsGood-Ark
    What it is
    N-channel MOSFET
    Maker
    Good-Ark
    Package
    SOT-883
    Pins
    3
    Details
    N-channel MOSFET, 60 V
    Source
    Manufacturer datasheet

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

  • GSMMBTRA101YSOT-23PNP transistor, 3 pins, Good-ArkPNP transistorSOT-233 pinsGood-Ark
    What it is
    PNP transistor
    Maker
    Good-Ark
    Package
    SOT-23
    Pins
    3
    Details
    PNP transistor, 50 V, 0.1 A
    Source
    Manufacturer datasheet

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

  • L2N7002KLT1GSOT-23N-channel MOSFET, 3 pins, LeiditechN-channel MOSFETSOT-233 pinsLeiditech
    What it is
    N-channel MOSFET
    Maker
    Leiditech
    Package
    SOT-23
    Pins
    3
    Source
    Manufacturer datasheet

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

  • 2 more parts have no package on record
    • BFCN-3010+RF filter, Mini-CircuitsRF filterNot recordedNot recordedMini-Circuits
      What it is
      RF filter
      Maker
      Mini-Circuits
      Package
      Not recorded
      Pins
      Not recorded
      Details
      LTCC filter, 2920-3100 MHz
      Source
      Manufacturer datasheet

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

    • BFR949L3RF transistor, InfineonRF transistorNot recordedNot recordedInfineon
      What it is
      RF transistor
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

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.

MOSFET

Diode range, part lifted. Test drain to source first, then short gate to source and test again.

Working, it reads

One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

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.
  • No body diode at all: failed open.
On the board
the gate usually has a resistor to the source, which reads as that resistor and 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.

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.

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.

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.

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.

NPN transistor

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

Working, it reads

Red 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.

Digital transistor

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.

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.

Codes that begin with RKs

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 4 more parts.

Did you find your part?

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