Skip to content
WhatSMDSign in

SMD code 4303

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.

4303 on a chip resistor

430 kΩ

430 kΩ resistor, 1%

430 followed by 3 zeros. Four digits is normally the 1% series.

Check it with a meter

Lift one end and measure across it. A good one reads 430 kΩ within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 430 kΩ on the board is a fault. Open, or well above 430 kΩ, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 430 kΩ. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.

On a transistor or diode body (SOIC-8), 4303 is a part code instead. Those parts are listed below.

2 parts are printed 4303

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • SM4303PSKSOIC-8P-channel MOSFET, Sinopower SemiconductorP-channel MOSFETSinopower Semiconductor
    What it is
    P-channel MOSFET
    Maker
    Sinopower Semiconductor
    Package
    SOIC-8
    Pins
    8
    Details
    30 V, 17.6 A P-channel MOSFET
    Source
    Manufacturer datasheet

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

    Datasheetfor SM4303PSK, opens in a new tab
  • 1 more part has no package on record
    • MTC4303N8JComplementary MOSFET pair (N-channel and P-channel), CYStekComplementary MOSFET pair (N-channel and P-channel)CYStek
      What it is
      Complementary MOSFET pair (N-channel and P-channel)
      Maker
      CYStek
      Package
      Not recorded
      Pins
      Not recorded
      Details
      30 V, 8.4/-5.4 A N+P-channel MOSFET
      Source
      Manufacturer datasheet

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

      Datasheetfor MTC4303N8J, 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.

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.

MOSFET pair

Diode range, part lifted. Test drain to source first, then short gate to source and test again. Test each MOSFET on its own pins, as the datasheet's pinout gives them.

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.

Did you find your part?

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