Help, bios won't post

Soldato
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27 Dec 2006
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Hi all

have a friend and his pc won't turn on properly. switch on and it starts for a sec then powers off immediately.

i opened it tried working ram from my PC and still no luck. I did not notice any burn smell or see any burn marks

- mobo is Asus P5B deluxe WIFI AP
- hard drive is 500g WD ( it is brand new and works on other comp)
- not sure what CPU he has - think its a dual core that is couple years old and not overclocked
- ram is crucial ballistic, I tried my sticks of ram and still same problem, so mem is not the issue
- power supply is Win Power 700w - doubt it's dead since the comp wouldn't even get power - could i be wrong?

is the motherboard dead or CPU? i tried switching the jumper to reset the bios but then it doesn't post anything?

thx for help
 
There could be a number of reasons. Some fatal and other easily fixed.

Illeminate all possibles by testing the ram and PSU on your kit. If they work then they are not the problem. Just continue like that till you find what does not work.

One thing I would do is check the CPU cooler. It might just be loose and not making contact to the CPU, have that the other day - booted for a sec then powered down. Bloke forgot to push the four mounting pin things down. Quick fix. :D
 
Could well be a PSU issue. Had one fail in a similar way. Swap in a known good PSU to check.

Winpower are not a very good brand.
 
PSU - why would that be the issue? surely it wouldn't get any power at all if it was blown thus not even turning on at all?

RAM - i swapped in my RAM and it still same problem. ruling out RAM as the issue

the comp starts to post the ASUS intro screen for 1 sec then it powers off then it tries to restart again and again - looping until I do a hard switch off


when i switch the jumper on board to slot 2 and 3 to reset then it won't even post on the screen like it does in default slot 1 and 2. this leads me to believe that the mobo has an issue.

anyway I ordered a new P5Q board and e6500, hopefully that will fix the problem

thx
 
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A broken PSU won't necessarily be totally dead. They can be instable and unable to provide enough current for the machine way before they go totally dead. They can also lose one or more of their rails yet the 12v one which you see semi-spinning the fans is still good.

I've had several (cheap and some not so) PSUs go on me in different ways. Only one was totally DOA and even that would power on by itself and show 12v, 5v and 3.3v lines when bench tested.
 
Essential for any PC toolkit is a multimeter and a PSU load tester. Saves the messing about swapping PSU's between machines and only costs a few pounds.

andy
 
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