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SMD code X4s

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 X4 was searched.

110 parts are printed X4s

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.

  • BZX84C68WSOT-323Zener diode, 3 pins, PanjitZener diodeSOT-3233 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-323
    Pins
    3
    Source
    Manufacturer datasheet

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

  • BZX84C68W-AUSOT-323Zener diode, 3 pins, PanjitZener diodeSOT-3233 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-323
    Pins
    3
    Source
    Manufacturer datasheet

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

  • BZX384C68SOD-323Zener diode, 2 pins, Taitron ComponentsZener diodeSOD-3232 pinsTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX384C68-Q1SOD-323Zener diode, 2 pins, Formosa MicrosemiZener diodeSOD-3232 pinsFormosa Microsemi
    What it is
    Zener diode
    Maker
    Formosa Microsemi
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX584C68SOD-523Zener diode, 2 pins, PanjitZener diodeSOD-5232 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-523
    Pins
    2
    Details
    68V, 150mW, Surface Mount Zener Diodes
    Source
    Manufacturer datasheet

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

  • BZX584C68-AUSOD-523Zener diode, 2 pins, PanjitZener diodeSOD-5232 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-523
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX784B6V2SOD-723Zener diode, 2 pins, SeCoSZener diodeSOD-7232 pinsSeCoS
    What it is
    Zener diode
    Maker
    SeCoS
    Package
    SOD-723
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX784C6V2SOD-723Zener diode, 2 pins, SeCoSZener diodeSOD-7232 pinsSeCoS
    What it is
    Zener diode
    Maker
    SeCoS
    Package
    SOD-723
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX984C6V2SOD-923Zener diode, 2 pins, RectronZener diodeSOD-9232 pinsRectron
    What it is
    Zener diode
    Maker
    Rectron
    Package
    SOD-923
    Pins
    2
    Source
    Manufacturer datasheet

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

  • CZRV52C68S-P2-HFSOD-323Zener diode, 2 pins, ComchipZener diodeSOD-3232 pinsComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SOD-323
    Pins
    2
    Details
    68 V 0.2 mW zener diode
    Source
    Manufacturer datasheet

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

  • GZF68CSOD-123FZener diode, 2 pins, Galaxy MicroelectronicsZener diodeSOD-123F2 pinsGalaxy Microelectronics
    What it is
    Zener diode
    Maker
    Galaxy Microelectronics
    Package
    SOD-123F
    Pins
    2
    Details
    68V, 5%, Surface Mount Zener Diodes
    Source
    Manufacturer datasheet

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

  • MM1Z6V8BWSOD-123Zener diode, 2 pins, YFWZener diodeSOD-1232 pinsYFW
    What it is
    Zener diode
    Maker
    YFW
    Package
    SOD-123
    Pins
    2
    Source
    Manufacturer datasheet

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

  • MMSZ22SOD-123Zener diode, 2 pins, onsemiZener diodeSOD-1232 pinsonsemi
    What it is
    Zener diode
    Maker
    onsemi
    Package
    SOD-123
    Pins
    2
    Details
    Zener Voltage Regulators MMSZxxxT1G Series, SZMMSZxxxT1G Series
    Source
    Manufacturer datasheet

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

  • MMSZ5237BSOD-123FZener diode, 2 pins, DiotecZener diodeSOD-123F2 pinsDiotec
    What it is
    Zener diode
    Maker
    Diotec
    Package
    SOD-123F
    Pins
    2
    Source
    Manufacturer datasheet

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

  • 1 more part has no package on record
    • FMOSAE0085P02MOSFET, Formosa MicrosemiMOSFETNot recordedNot recordedFormosa Microsemi
      What it is
      MOSFET
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

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.

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.

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.

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