PSU problem? PC powers for 1/2 second

[esko]

I decided to do some upgrading and purchased:
Intel QX6700
ASUS Striker Extreme Mobo
BFG 8800GTX OC
Corsair 8500 Dominator RAM
700 X-Power PSU

Now the system I had before the upgrading was working perfectly fine. Put together the new parts into the case, checked everything is connected fine then tried the power and there was a flicker of life from the fans for 1/2 sec and no beeps. Hmm. LCD reads CPU INIT so checked various forums and tried all the things like clear CMOS (making sure it is enabled), use lower voltage ram, tried various slots for the ram, tried without CPU, without ram. Everytime just getting this flicker of life from it.

Tried a different PSU and still just a flicker. After hours of trying I gave up thinking that maybe the Mobo is faulty.

Dicided to put together my original PC with all the original parts it was built with. When to power up and get a flicker of life from the fans again for 1/2 sec! Hmm. Tried swapping the PSU for the 700W and same thing again. Tried changing the power cord and still just a flicker. Tried a different wall socket for the power and still the same.

If anyone has any idea why this is happening then I'd be very grateful.

Thanks

[Giraffe]

"Tried a different wall socket for the power and still the same.
If anyone has any idea why this is happening then I'd be very grateful."

OK, so you've done all the substitution and I can't think of anything else to change, so a couple of [probably silly] suggestions:

do other things work off the wall sockets (could be full voltage but something limiting the current)? This is unlikely on a domestic circuit.

are you going via a UPS or surge suppressor?

Peter.

[killie99]

try and get hold of a PSU tester (scan do them, antec do them amongst others ... http://www.scan.co.uk/Products/Produ...oductID=391645 ) It could be that one of your power supplies is toast and has damaged both of your motherboards.

[BigBry]

Does it power up for the half second, shut down and you're then able to do the same thing again immediately? If there's a delay between the shutdown and being able to power up again it's a sign of a short circuit.

[Clunk]

Sounds familiar this.

You say you have tried another psu, what was it? Have you got the 8 pin power cable plugged into the board? Are the main power cables in fully?

If you can, try a different type and brand of psu, that should rule out any incompatibilities.

Build the pc up on some cardboard away from the case, that will rule out short circuits.

Try one stick of ram at a time in each of the slots (a long shot but worth a try).

Instead of using the case switch to turn on the motherboard, use something metallic to short the pins, that will rule out the power switch.

Failing that, sounds like a dead motherboard.

[esko]

Does it power up for the half second, shut down and you're then able to do the same thing again immediately? If there's a delay between the shutdown and being able to power up again it's a sign of a short circuit.

This is what it is happening. I seems like a short circuit. The mobo LED is lit along with the LEDs of the onboard switches. I will try the motherboard out of the case and see if it boots up.

[grayg1]

Do you have any spare standoffs screwd into the case where the motherboard sits that DON'T line up with the screwholes on the motherboard?
These things http://www.maplin.co.uk/images/full/37594i0.jpg

[esko]

It was a short circuit.

Tried it out of the case and it boots up ok now.

What a beast though. Need to start on OC it now

Thanks all

[Blitzen]

Give us a link to the PSU and i'll take a look. TBH though it sounds like a 'kipper' unit.