Intermittent boot issues - suggestions?

[Bablos]

Hi There...

I built a PC for my girlfriend in June last year, into which went this;

*OVERCLOCKED* AMD Phenom II X3 Tri Core 720 2.80GHz @ 3.50GHz / Gigabyte GA-MA790XT-UD4P Motherboard / Corsair 4GB DDR3 XMS3 PC2-1600C9DHX TwinX (2x2GB) Bundle
Sapphire ATI Radeon HD 4870 Vapor-X 1GB GDDR5 PCI-Express Graphics Card
Western Digital Caviar Black 640GB SATA-II 32MB Cache - OEM (WD6401AALS)
Antec 300 Three Hundred Ultimate Gaming Case - Black (No PSU)
LG GH22NS30 22x DVD±RW SATA Dual Layer ReWriter (Black) - OEM
650W Be Quiet Dark Power PRO BN073

She's been having problems getting the PC to boot - on occasion it'll boot up just fine. More frequently though, and increasing lately, she switches on and the machine doesn't even POST. Power and HD lights light up, DVD lights up, power and reset switches don't respond, so only option is the on/off switch at the back.

I've got a look inside the machine, and when it refuses to POST, the "FAILURE" light on the back of the graphics card lights up. On the odd occasion that it does boot up, that light stays off.

Has anyone seen this before? Is there a way to fix it, or does it mean that the graphics card is on it's way out?

I'd appreciate any feedback you guys can give.

Thanks in advance...

 

[Bablos]

So far I've restored defaults in the BIOS and it's booted up just fine, no matter how many times it's been power cycled. Once it's in situ and being used for a few days in it's normal way I'll have a better idea if things have improved.

I'll keep you posted...

 

[Bablos]

Well, she's booted it up this morning and it didn't even POST. I'll get her to try a few times later too.

The machine is back to defaults now, not overclocked.

Once she's back at home I can get her serial numbers from the video card, get in touch with Sapphire and see if they can offer up any insight into the FAILURE light being lit up most of the time.

I don't have a spare PSU of sufficient wattage in order to replace the existing one really in order to test it.

EDIT: Actually, I've got a 600W Tagan from my spare PC built 4 years ago or so. Any idea what kind of wattage I'd be looking at considering the specs above?

 

[Bablos]

*nods* that's the problem, it's labelled FAILURE, so not much of a code to work on really.

I'll get her to bring the machine over later, check the card for any mention of the alphanumerical codes.

 

[Bablos]

I've got the machine with me now, so I've checked the details on the card. The name of the LED that lights up is D1261, but I can't find any mention of it when I search.

I clearly didn't look far enough on the card though, as "FAILURE" is just above that LED, whereas the full text on the back of the card says;

"D1620/D1621: EXT 12V FAILURE"

So, looks like it is a PSU issue after all? I haven't noticed any other lights on the back of the card to indicate any other error. When the machine boots successfully, the same LED flashes a few times.

The PSU is modular, but there are only two PCIe power sockets, both of which are used by the 4870, so I can't even try another connection with it.