"No signal" on monitor and PC won't turn off...

[Ploper001]

Hi all,

A friend's PC that I built a few years ago is acting strangely. When the power cable is plugged into the power supply, the PC turns on automatically but half of the components do not turn on (the CPU fan at least is on, the DVD+RW drive, case fans and HDDs are off) and there is no signal to the monitor. The power and reset buttons do nothing so the only way to power it down is to unplug the power cable again.

I've tried a different power cable and a different power supply, the result is the same. I've also checked the front panel connectors and power supply connectors and they're all fine so I'm left thinking the only explanation is a dead motherboard. The weird thing though is that there haven't been any power cuts and AFAIK no power surges, "slowly dying" symptoms or anything so I don't know why the motherboard would just die like that but I can't think of another explanation.

Anyway, I just wanted to see if anyone could think of another potential cause before I order a new motherboard for it?


Thanks!

 

[G0AOZ]

Any beep codes from the system speaker?
Can you try the memory and CPU on a different motherboard?
Closely inspect the capacitors on the motherboard. Anything resembling the "bad caps" phenomenon? See

http://www.badcaps.net

for an explanation.
Have you tried completely removing the motherboard from the case and running it on the bench or table, just to ensure no short circuits underneath from a wayward bolt, etc?

ROGER - G0AOZ.

 

[BadBigBen]

addendum to G0AOZ's suggestions, CLR CMOS does wonders at times...

the symptoms described also speak of a bad BIOS flash...

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[Ploper001]

I have no other PCs that would take DDR RAM and none that would take a Socket 939 CPU either so I can't really test them . I did try to clear the CMOS, forgot to mention that - there was no change. I can't actually get another look at the capacitors until I next get to see the PC which might be after Christmas unfortunately.