Today my PC went dead!
When I say dead, I mean it: no PSU fan, no CPU fan, no case fan; no Beeps, no leds.
The only led that is on is on the back of the case close to the PSU, and it has always been on should the power cord be connected.
So I tried:
- Checked the cables (24 pin + 4 pin): they were OK
- Removed everything except RAM: did not change anything
- PSU: worked fine in another PC
- power button: works fine
- BIOS reset: did not change anything
- CMOS battery: 3.2V: OK
BUT, if I:
- disconnect the 24 pin connector from the motherboard
- short out the green wire to any black (earth) wire with a paper clip
- and then reconnect the 24 pin in the MB
then the PC turns ON magically and boots normally!
Only this sequence allows to turn on the PC: for example, if I short the green wire and the black wire when the connector is in the MB, then the PC does not start.
If this matters, one thing that I noted is that the back panel LED is brighter when the 24 pin connector is disconnected, while it gets weaker when I connect the connector in the MB.
(Does it makes sense?)
Looks like you have a short either in your MB or PSU that is drawing current. It could be either component, but I would lean towards MB. Do you have a different PSU you could try to see if that is the issue?