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SMD code H4

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.

21 parts are printed H4

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.

  • BZX384C7V5SOD-323Zener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-323
    Pins
    2
    Details
    7.5 V Zener diode
    Source
    From the manufacturer's datasheet

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

    Datasheetfor BZX384C7V5, opens in a new tab
  • BZX585-C8V2SOD-523Zener diode, 2 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-523
    Pins
    2
    Pinout
    • 1 cathode
    • 2 anode
    Details
    8.2 V approx. ±5% voltage regulator (Zener) diode
    Source
    From the manufacturer's datasheet

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

    Datasheetfor BZX585-C8V2, opens in a new tab
  • MMBZ5244ASOT-23Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMBZ5244A, opens in a new tab
  • MMBZ5244AWSOT-323Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-323
    Pins
    3
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMBZ5244AW, opens in a new tab
  • MMBZ5244BSOT-23Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMBZ5244B, opens in a new tab
  • MMBZ5244B-AUSOT-23Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMBZ5244B-AU, opens in a new tab
  • MMBZ5244BTWSOT-363Zener diode, 6 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-363
    Pins
    6
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMBZ5244BTW, opens in a new tab
  • MMBZ5244BWSOT-323Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-323
    Pins
    3
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMBZ5244BW, opens in a new tab
  • MMSZ5229BSOD-123FZener diode, 2 pins, Diotec
    What it is
    Zener diode
    Maker
    Diotec
    Package
    SOD-123F
    Pins
    2
    Details
    SMD Planar Zener Diodes
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5229B, opens in a new tab
  • MMSZ5244ASOD-123Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244A, opens in a new tab
  • MMSZ5244ASSOD-323Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244AS, opens in a new tab
  • MMSZ5244AS-AUSOD-323Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244AS-AU, opens in a new tab
  • MMSZ5244BSOD-123Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244B, opens in a new tab
  • MMSZ5244B-AUSOD-123Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244B-AU, opens in a new tab
  • MMSZ5244BSSOD-323Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244BS, opens in a new tab
  • MMSZ5244BS-AUSOD-323Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

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

    Datasheetfor MMSZ5244BS-AU, opens in a new tab
  • PUMH4SOT-363Digital transistor (NPN, resistors built in), 6 pins, Nexperia
    What it is
    Digital transistor (NPN, resistors built in)
    Maker
    Nexperia
    Package
    SOT-363
    Pins
    6
    Details
    50 V, 100 mA NPN/NPN resistor-equipped transistor; R1 = 10 kΩ, R2 = open
    Source
    From the manufacturer's datasheet

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

    Datasheetfor PUMH4, opens in a new tab
  • PUMH17SOT-363Digital transistor (NPN, resistors built in), 6 pins, Nexperia
    What it is
    Digital transistor (NPN, resistors built in)
    Maker
    Nexperia
    Package
    SOT-363
    Pins
    6
    Details
    50 V, 100 mA NPN/NPN resistor-equipped transistor; R1 = 47 kΩ, R2 = 22 kΩ
    Source
    From the manufacturer's datasheet

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

    Datasheetfor PUMH17, opens in a new tab
  • SN74LVC1G00DPWX2SONLogic gate, 5 pins, Texas Instruments
    What it is
    Logic gate
    Maker
    Texas Instruments
    Package
    X2SON
    Pins
    5
    Details
    Single 2-Input Positive-NAND Gate
    Source
    From the manufacturer's datasheet

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

    Datasheetfor SN74LVC1G00DPW, opens in a new tab
  • UMH4NSOT-363Digital transistor (NPN, resistors built in), 6 pins, JSCJ
    What it is
    Digital transistor (NPN, resistors built in)
    Maker
    JSCJ
    Package
    SOT-363
    Pins
    6
    Details
    Digital transistor (bias resistors built in), NPN, 100 mA
    Source
    From the manufacturer's datasheet

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

    Datasheetfor UMH4N, opens in a new tab
  • 1 more part has no package on record
    • BGH182MRF amplifier (MMIC), Infineon
      What it is
      RF amplifier (MMIC)
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: RF amplifier.

      Datasheetfor BGH182M, opens in a new tab

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.

RF amplifier

Voltage, board powered, on the output pin that the bias resistor or choke feeds.

Working, it reads

The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.

Dead, it reads

  • Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
  • Output pin at the full supply voltage: open inside, no current flowing.
On the board:
Measured on the board with power on; the bias network is part of the reading.
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 figures depend on the part and its bias resistor. The datasheet gives both.

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.

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.

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 H4

For a marking with its end worn or burnt off. Each code has a page of its own.

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