Tried all fixes, motherboard light's on but nobodies home

[haarrrllll]

A day ago my PC (which I've had for a few months) decided to turn itself off after it was on for around ten hours. I opened it up and rearranged the cables, because I had read if the system detects it may overheat, it just turns itself off. So, with new neat and tidy insides, my motherboard light would be on but the system wouldn't boot. I slept on it and voila, my PC worked this morning. However, it turned itself off after a few hours usage and wouldn't turn back on. I have spent all afternoon and night trying to fix it. I've tried the paper clip trick on the power supply and it runs. I've taken out the CMOS battery for 5 minutes. The only thing I haven't touched is the CPU, because I bought an overclocked bundle so I've never seen in there.

So, basically my PC won't boot with only the 24 pin & 8 pin power cables, CPU fan cable and the power switch cable plugged into the motherboard. The lights on too.

What on earth is wrong? :S

 

[bigwoofer]

I've seen MANY a dead power supply light up or even turn on its own fan, or even the CPU fan on the mobo but actually be dead. The paper clip trick is only closing the loop to activate the powersupply- but it's not texting your voltage across all your power outputs. If the paper clip trick doesn't power it up, sure enough it's dead. But if it does power it up, the powersupply can still be dead

Either hook it up to a $20 tester to see it's outputing 12V, 5V and other voltages properly OR replace with a known good power supply to trouble shoot - I bet it's your power supply. Good luck and let us know what you find!

Link to a tester:
http://www.ebay.com/itm/like/270590746774?lpid=82

 

[johnnyb105]

+1 Power Supply is bad.

 

[haarrrllll]

So it's on right now. But I just saw the screen turn black and I thought I was witnessing it shutting down, so I powered it down by holding the power switch for a few seconds. I currently have it in ASUS BIOS mode - Is there a way of checking whats wrong from here? Surely the power supply is OK if it will turn on and stay on for a few hours, but then shut down?

 

[haarrrllll]

In terms of power, from the advanced BIOS mode I can see these figures:

CPU input voltage (VVCIN) = + 1.584V or 1.600V (it changes)
CPU core voltage = +0.982V
3.3V voltage = +3.328V
5V voltage = +5.120V
12V voltage = +11.904V or 12.000V (it changes)

should these figures be exactly on 3.3, 5 and 12V respectively, or are these close enough?