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SMD code E8

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.

12 parts are printed E8

Not sure which one you have?

Answer up to 4 quick questions and these 12 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • BZD27C20PSOD-123FZener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-123F
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • BZT52-B51SOD-123Zener diode, 2 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • BZT52H-B39SOD-123FZener diode, 2 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-123F
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • BZX84C3V0SOT-23Zener diode, 3 pins, Diotec
    What it is
    Zener diode
    Maker
    Diotec
    Package
    SOT-23
    Pins
    3
    Details
    SMD Planar Zener Diodes
    Source
    From the manufacturer's datasheet

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

  • BZX384C4V3SOD-323Zener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-323
    Pins
    2
    Details
    4.3 V Zener diode
    Source
    From the manufacturer's datasheet

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

  • BZX585-B12SOD-523Zener diode, 2 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-523
    Pins
    2
    Pinout
    • 1 cathode
    • 2 anode
    Details
    12 V ±2% voltage regulator (Zener) diode
    Source
    From the manufacturer's datasheet

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

  • MMDT5214WSOT-323Digital transistor (resistors built in), 3 pins, Diotec
    What it is
    Digital transistor (resistors built in)
    Maker
    Diotec
    Package
    SOT-323
    Pins
    3
    Details
    SMD Digital NPN Transistors
    Source
    From the manufacturer's datasheet

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

  • MMSZ5233SOD-123Zener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-123
    Pins
    2
    Details
    6 V Zener diode
    Source
    From the manufacturer's datasheet

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

  • MMSZ5233-GSOD-123Zener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-123
    Pins
    2
    Details
    6 V Zener diode
    Source
    From the manufacturer's datasheet

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

  • TLV75511PDQNX2SONLDO regulator, 4 pins, Texas Instruments
    What it is
    LDO regulator
    Maker
    Texas Instruments
    Package
    X2SON
    Pins
    4
    Details
    500mA, Low-IQ, Small-Size, Low-Dropout Regulator
    Source
    From the manufacturer's datasheet

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

  • 2 more parts have no package on record
    • BZT52C3V9KZener diode, Taiwan Semiconductor
      What it is
      Zener diode
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

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

    • ESD0P8RFLESD protection diode, Infineon
      What it is
      ESD protection diode
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: TVS or ESD protection diode.

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.

TVS or ESD protection diode

Diode range, from the protected line to ground, part lifted if you can.

Working, it reads

A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

Dead, it reads

  • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
  • A reading both ways on a one-way part: leaky.
  • A one-way part open both ways: failed open.
On the board
, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
Compare:
The same part on the next line or connector pin is the healthy reading to compare with.
Watch for:
A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

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.

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.

Printed with a code easy to misread as E8

One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.

Codes that begin with E8

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.