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SMD code FR in SOT-523

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.

Not sure which one you have?

Answer up to 4 quick questions and these 35 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • 2SA1774-RSOT-523PNP transistor, Galaxy MicroelectronicsPNP transistorGalaxy Microelectronics
    What it is
    PNP transistor
    Maker
    Galaxy Microelectronics
    Package
    SOT-523
    Pins
    3
    Details
    -50V, -0.15A, General Purpose PNP Bipolar Transistor
    Source
    Manufacturer datasheet

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

  • 2SA1774CR-R-CSOT-523Transistor, SeCoSTransistorSeCoS
    What it is
    Transistor
    Maker
    SeCoS
    Package
    SOT-523
    Pins
    3
    Details
    Bipolar transistor
    Source
    Manufacturer datasheet

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

  • T2SA1774-RSOT-523PNP transistor, Galaxy MicroelectronicsPNP transistorGalaxy Microelectronics
    What it is
    PNP transistor
    Maker
    Galaxy Microelectronics
    Package
    SOT-523
    Pins
    3
    Details
    -50V, -0.15A, General Purpose PNP Bipolar Transistor
    Source
    Manufacturer datasheet

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

  • BTA1774C3SOT-523PNP transistor, CYStekPNP transistorCYStek
    What it is
    PNP transistor
    Maker
    CYStek
    Package
    SOT-523
    Pins
    3
    Details
    -50 V, -0.15 A PNP transistor
    Source
    Manufacturer datasheet

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

  • 2SA1774SOT-523Galaxy MicroelectronicsNot recordedGalaxy Microelectronics
    What it is
    Not recorded
    Maker
    Galaxy Microelectronics
    Package
    SOT-523
    Pins
    3
    Details
    Si-pnp: GP, 60V, 100mA, 150mW, B=150..560, 140MHz
    Source
    Published code list

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

  • 10 more parts have no package on record. Nothing rules them out, so they stay.
    • L2SA1774RT1GPNP transistor, LRCPNP transistorLRC
      What it is
      PNP transistor
      Maker
      LRC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Bipolar transistor, PNP, IC 150 mA, VCEO 50 V
      Source
      Manufacturer datasheet

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

    • MM5Z3V0BZener diode, Formosa MicrosemiZener diodeFormosa Microsemi
      What it is
      Zener diode
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • MM5Z3V0B-Q1Zener diode, Formosa MicrosemiZener diodeFormosa Microsemi
      What it is
      Zener diode
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • S-L2SA1774RT1GPNP transistor, LRCPNP transistorLRC
      What it is
      PNP transistor
      Maker
      LRC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Bipolar transistor, PNP, IC 150 mA, VCEO 50 V
      Source
      Manufacturer datasheet

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

    • 2SA1576UBPNP transistorPNP transistorNot recorded
      What it is
      PNP transistor
      Maker
      Not recorded
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Published code list

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

    • 2SA1577QNot recordedNot recorded
      What it is
      Not recorded
      Maker
      Not recorded
      Package
      Not recorded
      Pins
      Not recorded
      Details
      see 2SA1037K above
      Source
      Published code list

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

    • 2SA1774EBPNP transistor, ROHMPNP transistorROHM
      What it is
      PNP transistor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Published code list

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

    • 2SA1774EBRROHMNot recordedROHM
      What it is
      Not recorded
      Maker
      ROHM
      Package
      Not recorded
      Pins
      3
      Details
      equivalent 2SA933ASR
      Source
      Published code list

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

    • BD48L29GVoltage supervisor, ROHMVoltage supervisorROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage Detector
      Source
      Published code list

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

    • BD4935FVEVoltage supervisor, ROHMVoltage supervisorROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS-IC: Voltage Detector 3,5V, Reset Push-pull output
      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.

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.

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.

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.

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.

Codes that begin with FR

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 23 more parts.

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