Problem, and not sure what caused it

[Phoenix Flight]

I built my PC nearly 2 years ago now and just lately it's been driving me up the wall.
It just won't ever seem to boot up first time. Sometimes it'll just flash on for a second before going off again, and it'll just continue to do this, I've left it going for about half an hour before getting fed up and switching it off. Sometimes it'll switch on fine but nothing else, no beep code, nothing on the monitor. And then on very rare occasions it'll actually start up and run perfectly fine.
I've replaced just about everything to find out what the problem is, I think it might be the power supply but like I said sometimes it'll run just fine so I don't know if it is the PSU.

Any other ideas before I go buying parts I don't need would be greatly appreciated.

[Katreat]

Are you sure it is hardware? Have you tried wiping the HD and re-installing the OS?

Kat

[Phoenix Flight]

I haven't tried that, no, hadn't even thought of it actually. Might have to try but I'd rather leave that as a last resort.

[shadowpr]

List parts, make and model including power supply.

Also might want to try this to help figure out what part it is: http://forum.pcmech.com/showthread.php?t=132409

Also tell us what you have replaced.

If it won't even post, then I'd think it's hardware related.

[Phoenix Flight]

Abit AN8 32X
Levicom vp450W
Geforce 7800GTX
AMD Athlon 64 X2 3800+
CRUCIAL 1GB DDR PC3200 400MHz X2
XFX GeForce 7800 GTX 256MB
Plextor PX-230A 52x32x52x CD-RW
Pioneer DVR-111DBK 16x DVD±RW

Out of those I've replaced the RAM and graphics card, not as much as I'd thought actually, but the other PC's are much older and they were the only parts compatable.

[shadowpr]

Try to see if it will post with that out of case build.

If not, then get a good power supply: http://forum.pcmech.com/showthread.php?t=131195

[Phoenix Flight]

OK, tried that and no luck. Looks like a new power supply then. Fingers crossed that'll sort it, annoying beyond belief when it takes hours just to get my PC on.

[shadowpr]

Keep us posted. If you change the power supply, and still can't get it to post, then let us know as well, and we'll take it from there.

[Phoenix Flight]

Been thinking about getting a new case too so I might get one of these (http://www.ebuyer.com/product/128045). Looking around at reviews the PSU has scored very well and should be plenty able to run my PC.

Also, I did notice something when I was running it out of the case, it still wouldn't start properly but it wasn't flashing on and off anymore.

[shadowpr]

That case and power supply combo is good.

[Phoenix Flight]

Well I got my new case and power supply, set it all up, and still not working. :mad:

[Phoenix Flight]

OK, so I've got a new mobo and now I'm getting a beep code error. Long, continuous beeps. And C1 on the POST display. :mad:

[aram]

hi Phoenix

It sounds like it must be a hardware problem if its not even posting. From reading the other posts, you've narrowed it down to the CPU or the CD/DVD drives.
Although pretty unlikely its easy to get the drives ruled out; just unplug them both and switch it on. If you still have the same problem, then you know its the CPU, which i think is most likely.

I honestly thought it would be the PSU, it sounded like unstable voltage output, but it would also be consistent with CPU having problems using that voltage.

Unfortunately you may find it difficult to find a s939 x2 processor these days, but you can pick up an equivalent single core for about £25, which should at least let you use your computer normally ;)

[Phoenix Flight]

I think it must be the CPU because I sent that mobo back and got a replacement which is having the exact same problem, and the CPU is the only part I haven't tried replacing. So that means spending even more money on this damn thing.