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SMD code 4Gt

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, t, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and 4G was searched.

36 parts are printed 4Gt

Not sure which one you have?

Answer up to 4 quick questions and these 36 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • APX803L05-18C3SOT-323Voltage supervisor, 3 pins, Diodes IncorporatedVoltage supervisorSOT-3233 pinsDiodes Incorporated
    What it is
    Voltage supervisor
    Maker
    Diodes Incorporated
    Package
    SOT-323
    Pins
    3
    Details
    Voltage detector IC: 1.8V±1.5%, -Reset ODO, Rdt=55ms
    Source
    Published code list

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

  • BC850CWSOT-323Transistor, 3 pins, InfineonTransistorSOT-3233 pinsInfineon
    What it is
    Transistor
    Maker
    Infineon
    Package
    SOT-323
    Pins
    3
    Details
    Bipolar transistor
    Source
    Published code list

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

  • DDZ3V3ASFSOD-323Zener diode, 2 pins, Diodes IncorporatedZener diodeSOD-3232 pinsDiodes Incorporated
    What it is
    Zener diode
    Maker
    Diodes Incorporated
    Package
    SOD-323
    Pins
    2
    Details
    Zener diode: 3.16..3.38V, Izt=20mA, Zzt=130, 500mW
    Source
    Published code list

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

  • FMMT2484SOT-233 pinsNot recordedSOT-233 pinsNot recorded
    What it is
    Not recorded
    Maker
    Not recorded
    Package
    SOT-23
    Pins
    3
    Details
    Si-npn: AF, LN, 60V, 50mA, 330mW, B=100..500, >100MHz
    Source
    Published code list

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

  • KIA7431FSOT-89Voltage supervisor, 3 pins, KECVoltage supervisorSOT-893 pinsKEC
    What it is
    Voltage supervisor
    Maker
    KEC
    Package
    SOT-89
    Pins
    3
    Details
    Lin/Digi-IC: Voltage Detector 3.1V, Reset Open collector output
    Source
    Published code list

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

  • MMBV2101SOT-233 pins, onsemiNot recordedSOT-233 pinsonsemi
    What it is
    Not recorded
    Maker
    onsemi
    Package
    SOT-23
    Pins
    3
    Details
    MV2101 varicap
    Source
    Published code list

    Is it dead? The meter test is below: PIN diode or varicap.

  • MMVL2101SOD-3232 pins, onsemiNot recordedSOD-3232 pinsonsemi
    What it is
    Not recorded
    Maker
    onsemi
    Package
    SOD-323
    Pins
    2
    Details
    C-diode: FM/VHF-Tun., 30V, 200mA, 6,1..7,5pF(4V, 1MHz)
    Source
    Published code list

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

  • MMVL2101T1SOD-3232 pins, onsemiNot recordedSOD-3232 pinsonsemi
    What it is
    Not recorded
    Maker
    onsemi
    Package
    SOD-323
    Pins
    2
    Source
    Published code list

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

  • PT7M824YSESOT-353Voltage supervisor, 5 pins, Diodes IncorporatedVoltage supervisorSOT-3535 pinsDiodes Incorporated
    What it is
    Voltage supervisor
    Maker
    Diodes Incorporated
    Package
    SOT-353
    Pins
    5
    Details
    Voltage detector IC: 2.19V±1%, ±Reset PPO, WD
    Source
    Published code list

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

  • R3117K371CDFNVoltage supervisor, RicohVoltage supervisorDFNNot recordedRicoh
    What it is
    Voltage supervisor
    Maker
    Ricoh
    Package
    DFN
    Pins
    Not recorded
    Details
    Voltage detector IC: 3.7V±1%, -Reset PPO, Sense
    Source
    Published code list

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

  • R3131N24EASOT-233 pins, Nisshinbo Micro DevicesNot recordedSOT-233 pinsNisshinbo Micro Devices
    What it is
    Not recorded
    Maker
    Nisshinbo Micro Devices
    Package
    SOT-23
    Pins
    3
    Details
    CMOS-IC: Voltage Detector 2,4V, Reset Push-pull output, 240ms
    Source
    Published code list

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

  • R5105N451CSOT-23-6Voltage supervisor, 6 pins, RicohVoltage supervisorSOT-23-66 pinsRicoh
    What it is
    Voltage supervisor
    Maker
    Ricoh
    Package
    SOT-23-6
    Pins
    6
    Details
    Voltage detector IC: 4.5V±1%, -Reset PPO
    Source
    Published code list

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

  • 3 more parts have no package on record
    • CDZ55C4V7TZener diode, Crownpo TechnologyZener diodeNot recordedNot recordedCrownpo Technology
      What it is
      Zener diode
      Maker
      Crownpo Technology
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 4.47..4.94V, Zzt=70, Izt=5mA, 200mW
      Source
      Published code list

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

    • MIC5380-1.8/1.2YFTLDO regulator, MicrelLDO regulatorNot recordedNot recordedMicrel
      What it is
      LDO regulator
      Maker
      Micrel
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out, Vo1/Vo2=1.8V/1.2V±2%, 150mA, +CE
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

    • R1161D241BNisshinbo Micro DevicesNot recordedNot recordedNot recordedNisshinbo Micro Devices
      What it is
      Not recorded
      Maker
      Nisshinbo Micro Devices
      Package
      Not recorded
      Pins
      Not recorded
      Details
      VR-IC: LDO, CE, 2.4V±2%, 350mA
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

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.

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.

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.

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.

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.

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.

PIN diode or varicap

Diode range, part lifted or one leg off the pad. Red probe on the anode.

Working, it reads

About 0.6 to 0.9 V anode to cathode, 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.
  • 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 varicap that has drifted in capacitance reads normal on a meter. Only a capacitance meter or the tuning itself shows it.

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.

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