SMD code S42 in SMC
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.
1 part in SMC is printed S42
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.
Schottky diode. What differs:
STPS4S200SSMC2 pins, STMicroelectronics2 pinsSTMicroelectronics
- What it is
- Schottky diode
- Maker
- STMicroelectronics
- Package
- SMC
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
2 more parts have no package on record. Nothing rules them out, so they stay.
BAS40ADWSTaitron ComponentsNot recordedTaitron Components
- What it is
- Schottky diode
- Maker
- Taitron Components
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Schottky Barrier Diodes (Multiple Terminals)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
BAT40AWSTaitron ComponentsNot recordedTaitron Components
- What it is
- Schottky diode
- Maker
- Taitron Components
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Schottky Barrier Diodes (Multiple Terminals)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky 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.
Schottky diode
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- A reading the wrong way round as well: leaky.
- Open both ways: failed open.
- 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 large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.
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 S42
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 S42
For a marking with its end worn or burnt off. Each code has a page of its own.
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Open this in the search to correct a character or try another package.