SMD code 1205
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.
1205 on a chip resistor
12 MΩ
12 MΩ resistor, 1%
120 followed by 5 zeros. Four digits is normally the 1% series.
Check it with a meter
Lift one end and measure across it. A good one reads 12 MΩ within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 12 MΩ on the board is a fault. Open, or well above 12 MΩ, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 12 MΩ. 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 (SOT-23, DFN), 1205 is a part code instead. Those parts are listed below.
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.
The only part printed 1205 in our tables
LCE1205
- What it is
- Complementary MOSFET pair (N-channel and P-channel)
- Maker
- Leiditech
- Package
- DFN
- Pins
- Not recorded
- Details
- N+P channel MOSFET pair
- Source
- Manufacturer datasheet
Is it dead?
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.
Was it this one?
Printed with a code easy to misread as 1205
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 1205
For a marking with its end worn or burnt off. 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.