PC power flicking on then stopping...

Monkey Puzzle · 10 Aug 2008 at 17:07

My pc turned itself off last night. When I turn it back on the power flicks on for a fraction of a second, the fans just start spinning then it powers off. The PSU needs to be turned off until the motherboard light switches off before it'll do the same again.

I've unplugged everything except for the motherboard and graphics card, reset the CMOS for 5-10 minutes, taken out RAM and tried with just one stick, but no joy. Any suggestions what the problem might be?

Firegod · 10 Aug 2008 at 17:25

You say it switched off by itself, have you tried perhaps a different kettle lead into the PSU from your mains, and also a different socket in case this is the issue. If not, it could either be your PSU on the way out or the mobo. Is the PSU new or a decent make?

Cheers.

Monkey Puzzle · 10 Aug 2008 at 17:36

Thanks for your input - the PSU is a 600w Enermax noisetaker, which has been running for just over a year, and without receipt anyway if that's the problem.

After reseating another RAM stick the pc now powers on but with no video output and no beeping....

Going to try an old PCI graphics card my brother has lying around and see if that's where the problem is...

Firegod · 10 Aug 2008 at 17:41

Monkey Puzzle said:
Thanks for your input - the PSU is a 600w Enermax noisetaker, which has been running for just over a year, and without receipt anyway if that's the problem.

...

Going to try an old PCI graphics card my brother has lying around and see if that's where the problem is...

Fingers crossed!

The Enermax stuff is usually pretty solid, my last PSU was Enermax. I then bought an Antec NeoPower which died, so I bought my latest one which is an OCZ jobby. Rock solid.

DIABLO · 10 Aug 2008 at 17:42

that happened to me a few months back.. terns out the psu died. Try starting it without it being conncted to the motherboard.

Monkey Puzzle · 10 Aug 2008 at 19:09

Hmmm, well no joy using an old Geforce PCI graphics card, so that probably leaves the PSU or motherboard? :confused:

Time to try the PSU unconnected to the pc as suggested and with a multimeter I guess.

Monkey Puzzle · 10 Aug 2008 at 23:10

Tested the PSU with a multimeter and the voltages rails seem as per normal (12.19v, 5.1v ish and 3.8v), and it's powering the fans and pump okay, and motherboard light on, but nothing else happens when it's turned on. Really annoying me now. :mad:

Would it be fair to assume it's a motherboard problem then?

Firegod · 11 Aug 2008 at 17:44

Monkey Puzzle said:
Tested the PSU with a multimeter and the voltages rails seem as per normal (12.19v, 5.1v ish and 3.8v), and it's powering the fans and pump okay, and motherboard light on, but nothing else happens when it's turned on. Really annoying me now.

Would it be fair to assume it's a motherboard problem then?

I'd say so if you've tested the PSU like..