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Due to a broken fan retention module, I had to take the motherboard out of the chassis. After connecting everything back, everything seems to work (fans and HDs are spinning, network adapter's lights are flashing, etc...) but I get no display. I tried two different display adapters, tried disconnecting all other expansion cards but nothing seemed to work.

Update: just noticed that some of the usb connections aren't getting any power as well (after double checking, it seems that different devices seem to be giving different results regarding that one - mouse has its light on, wireless network adapter does not).

Some more updates: After some investigation, the situation looks like this - after power on, all fans are spinning, HDs are spinning, and CD-ROM is looking for media. However, it doesn't look like the OS is loading, since other than some flashing at the first few seconds, the HD activity led doesn't report any activity (the HDs are definitely spinning). I'm start to worry that perhaps the CPU was damaged before all this process began (as the cpu fan retention was broken), but it usually powers off on high temperature.

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Any beeps, or error codes displayed on the motherboard? – caliban Sep 8 '09 at 8:25
Exactly, does the BIOS produce some beepcode? (Google for the beepcodes of your specific motherboard) – Colin Sep 8 '09 at 8:26
I hear no beeps, can't really see any error code – On Freund Sep 8 '09 at 8:29
up vote 2 down vote accepted

My advice would be to take this to a computer repairman (unless you're one yourself).

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That's eventually what I did as everything else failed. Still waiting for the response, but it seems that the motherboard is wrecked... – On Freund Sep 15 '09 at 13:05

Is it possible it's this problem with the second power connector?

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Both are firmly connected – On Freund Sep 8 '09 at 8:32
What model is your motherboard? – Col Sep 8 '09 at 10:27
Gigabyte K8N Ultra-9 (socket 939, the processor is an AMD Athlon 64 bit) – On Freund Sep 8 '09 at 11:48

The first step in debugging this is to take the motherboard & PSU out of the chassis and just connect the bare essentials to get the board booting:

  1. CPU & Fan
  2. 1 DIMM module
  3. Power Supply
  4. PCI Port 80 POST if you don't have a POST card. A PCI Port 80 POST card can be had at a local computer shop for a few bucks (if you're lucky). Memory test with a Phoenix BIOS is 60h. We'll have to look it up with the other BIOS's.

If you can get past memory checking, then add one piece at a time until it fails or until you have a full system back together.

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Is the screen power firmly in, and is there a on / off switch on the screen?

Do you get a green light even when not plugged in to the pc?

Not sure your exact problem, but try to get the screen working first without being plugged in to the computer.

When done - simply try again, if you have another computer or laptop, try linking the screen up to that to make sure it isn't dead.

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Already tried two screens, both are confirmed to be working with other computers. – On Freund Sep 8 '09 at 8:28
Well, the other way around - do you have another screen you can test with this computer! – William Hilsum Sep 8 '09 at 8:58
Yes. I tried two screens, both worked with different computers, but not with the problematic one – On Freund Sep 8 '09 at 9:01
As you suspect CPU damage, do you have an available CPU for the same socket to try, and another working PC to place the suspect CPU in? – Bonus Sep 8 '09 at 10:05
Unfortunately no... – On Freund Sep 8 '09 at 11:47

What is your motherboard resting on? Have you checked for the possiblity of a short on the motherboard? Make sure it is resting on something non-conductive (I've used cardboard in the past).

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The chassis has mounts that it rests on, and it's screwed to the mounts. – On Freund Sep 8 '09 at 14:40

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