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SMD code K4 in MicroPak2

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 21 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • NC7SP17FHMicroPak2Logic gate, onsemiLogic gateonsemi
    What it is
    Logic gate
    Maker
    onsemi
    Package
    MicroPak2
    Pins
    6
    Details
    TinyLogic ULP-A Buffer with Schmitt-Trigger Input
    Source
    Manufacturer datasheet

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

  • 14 more parts have no package on record. Nothing rules them out, so they stay.
    • MMBZ5254BWSZener diode, Taitron ComponentsZener diodeTaitron Components
      What it is
      Zener diode
      Maker
      Taitron Components
      Package
      Not recorded
      Pins
      Not recorded
      Details
      SMD Zener Diodes (Three Terminals) - 200mW
      Source
      Manufacturer datasheet

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

    • NCV8135AMTW120LDO regulator, onsemiLDO regulatoronsemi
      What it is
      LDO regulator
      Maker
      onsemi
      Package
      Not recorded
      Pins
      Not recorded
      Details
      500 mA, Very Low Dropout Bias Rail CMOS Voltage Regulator
      Source
      Manufacturer datasheet

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

    • PSBD3DH40V1HSchottky diode, PrisemiSchottky diodePrisemi
      What it is
      Schottky diode
      Maker
      Prisemi
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Schottky diode, 40 V, 1 A
      Source
      Manufacturer datasheet

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

    • SS14HEWS-HFSchottky diode, ComchipSchottky diodeComchip
      What it is
      Schottky diode
      Maker
      Comchip
      Package
      Not recorded
      Pins
      Not recorded
      Details
      40 V, 1 A Schottky barrier diode
      Source
      Manufacturer datasheet

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

    • AP8821N-24GIVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
      What it is
      Voltage supervisor
      Maker
      Anwell Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.4V±2%, -Reset ODO, H-free
      Source
      Published code list

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

    • AP8821N-24GSVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
      What it is
      Voltage supervisor
      Maker
      Anwell Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.4V±2%, -Reset ODO, H-free
      Source
      Published code list

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

    • AP8821N-24PIVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
      What it is
      Voltage supervisor
      Maker
      Anwell Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.4V±2%, -Reset ODO
      Source
      Published code list

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

    • AP8821N-24PSVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
      What it is
      Voltage supervisor
      Maker
      Anwell Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.4V±2%, -Reset ODO
      Source
      Published code list

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

    • BD46E445G-MVoltage supervisor, ROHMVoltage supervisorROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 4.4V±1%, -MR, -Reset PPO, Rdt=50ms
      Source
      Published code list

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

    • EC95808N24C7IVoltage supervisor, E-CMOSVoltage supervisorE-CMOS
      What it is
      Voltage supervisor
      Maker
      E-CMOS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.4V±2%, -Reset ODO
      Source
      Published code list

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

    • EC95808N24C7SVoltage supervisor, E-CMOSVoltage supervisorE-CMOS
      What it is
      Voltage supervisor
      Maker
      E-CMOS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.4V±2%, -Reset ODO
      Source
      Published code list

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

    • LDTB113EET1GDigital transistor (PNP, resistors built in), LRCDigital transistor (PNP, resistors built in)LRC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      LRC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      PNP transistor: Sw., 50V, 500mA, B>39, R1/R2=1k/1k
      Source
      Published code list

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

    • NC7SP17FFairchild SemiconductorNot recordedFairchild Semiconductor
      What it is
      Not recorded
      Maker
      Fairchild Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Buffer with Schmitt-trigger input
      Source
      Published code list

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

    • NC7SP17LFairchild SemiconductorNot recordedFairchild Semiconductor
      What it is
      Not recorded
      Maker
      Fairchild Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Buffer with Schmitt-trigger input
      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.

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.

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.

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.

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.

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.

Codes that begin with K4

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 6 more parts.

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