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Thread ID: 51320 2004-11-17 21:09:00 M/board & Power Supply problem Stumped Badly (348) Press F1
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293340 2004-11-17 21:09:00 I replaced the Power supply in my kids computer a year ago with a new $50 300w cheapie, (yes I know) & the next day the motherboard died.
I chucked it in a corner & built a new one.
I started assembling another one a few days ago & used the "new" power supply that I had put in the kids old machine.
The board booted up ok & everything was as it should be.
Detected CPU, Ram etc.
Powered off & restarted, NOTHING!
Power lights on the board are on, CPU fan whirring round, the green power on light on the monitor comes on for 20secs nothing onscreen, then the monitor lights turn to amber & that's it.
Bugger I thought dud board, do all the clear CMOS etc still no good.

I get another board, (different brand) SAME THING
Powers up fine first time & upon restarting all fans lights etc are going, monitor does the same thing, powers on then off 20secs later.
Tried another monitor, same result.
It's obviously a crook power supply that has fried these 3 boards
I've tried another supply with the same results so the boards are definitely shot

My question is,
how do you test a power supply for faults so when I take it back to the supplier I can tell them what is wrong & that it has stuffed a few hundred $$ worth of Motherboards!!!

Thanks
Stumped
Stumped Badly (348)
293341 2004-11-17 22:18:00 As far as I know the only way to test the voltages on a power supply is on a running system so that the power supply is under load but this does not sound like an option in this case. Davesdad (923)
293342 2004-11-17 23:29:00 You could grab a small peice of wire and short out the green and black wires on the 20pin ATX header, this will turn the PSU on without it being connected to the PC. Then use a multimeter to check the rails to make sure there doing there job. Im not sure whether the rails will need to be under load for this to work, one of the electrical gurus will know. Pete O'Neil (250)
293343 2004-11-17 23:56:00 Thanks for the replies guys.
I did a google for "test a PSU" DOH!! should have done that 1st.
Came up with some good stuff
Particularly liked this one, so it's off to buy a multimeter
www.ochardware.com
Thanks again
Stumped Badly (348)
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