Skip to content
WhatSMDSign in

SMD code YYI

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.

3 parts are printed YYI

Not sure which one you have?

Answer up to 4 quick questions and these 3 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • RN2968FESOT-5636 pins, ToshibaNot recordedSOT-5636 pinsToshiba
    What it is
    Not recorded
    Maker
    Toshiba
    Package
    SOT-563
    Pins
    6
    Details
    Si-pnp-Digi: Dual, Sw, 50V, 100mA, 100mW, R1/R2=22k/47k
    Source
    Published code list

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

  • 2 more parts have no package on record
    • AP4457JYP-channel MOSFET, Advanced Power ElectronicsP-channel MOSFETNot recordedNot recordedAdvanced Power Electronics
      What it is
      P-channel MOSFET
      Maker
      Advanced Power Electronics
      Package
      Not recorded
      Pins
      Not recorded
      Details
      30 V, 9 A P-channel MOSFET
      Source
      Manufacturer datasheet

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

      Datasheetfor AP4457JY, opens in a new tab
    • RN2968ToshibaNot recordedNot recordedNot recordedToshiba
      What it is
      Not recorded
      Maker
      Toshiba
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Si-pnp-Digi: Dual, Sw, 50V, 100mA, 200mW, R1/R2=22k/47k
      Source
      Published code list

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

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.

P-channel MOSFET

Diode range, part lifted. Test drain to source first, then short gate to source and test again.

Working, it reads

Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

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. Often all three pins end up shorted together.
  • No body diode at all: failed open.
On the board
the gate usually has a resistor to the source, so gate to source reads that resistor, which 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.

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.

Printed with a code easy to misread as YYI

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

Did you find your part?

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