Computer Locks up and won't start...

[Arobein]

...so I have to open the case, remove the CPU and it's fan, and leave it open for about 15-20 minutes. After that I put the parts back in their places and pray to Odin for it to work. Sometimes it does, sometimes it does not. I have to do this about 3-5 times a day and it's getting frustrating.
I've tested RAM, CPU and Graphics card - all are working fine.
My comp usually just freeze and I have to turn it off (reset button won't work). After that I can't turn it on without the upper mentioned "fix". The comp would have all the lights on and fans are whirring, but the screen stays black and no lights are lit on my keyboard (although they do flash as soon as I start the comp). I can't figure out if it's my Motherboard or HDD or something else, but I'd like to hear from people who've encountered similar problem or know anything about it.
Thank you

 

[Tedster]

read the no P.O.S.T. guide in the guides forum. start simple.

check your drivers.
also check your PSU with a tester
you say you checked ram - with what? use memtest 86+ for at least 7 passes booted from a floppy.

 

[Arobein]

All drivers and BIOS are up-to-date. Spent several hours testing RAM with memtest. And I've got brand new PSU. I had the same problem with my old PSU, that's why I replaced it. But it isn't the PSU that's causing it.

 

[CCT]

The cpu could have a failing memory cache or internal problems.

Do you not have some mini-dumps or event viewer acivity?

Next time it does that, DON'T remove the cpu - just unplug the comp and press the power button to discharge the stored comp energy then try a reboot after a few minutes (which proves very little but would be interesting anyway).

 

[nickc]

Arobein, u say u have a new PSU but u did not tell any thing about it. if it is an off brand or came with the case? that could be the first thing to look at. give us the make, model, and amps on the 12volt rails of the PSU.

 

[Arobein]

CCT, no minidumps, cause my comp doesn't BSOD anymore. Just freezes.
Nickc, hxxp://www.amazon.co.uk/exec/obidos/ASIN/B000KGYMGW/202-8923953-6327864 this is my new PSU. Had it tested on another computer with no problems.

 

[CCT]

You have ALL connectors to the mobo on (eg, the extra 6/8 pin if needed) ?

 

[Arobein]

Yup. Mobo gets enough power. I can still turn the comp on. Sometimes if I can't start it I just replace my newer CPU for my old one and it works. And the other way around.

 

[waylander]

Does your mobo support beep error codes? If so try this:
Next time your computer locks up, remove the RAM then try restart it. If you hear no beeping it's most likely your mobo that's causing the problem.

 

[Arobein]

I'll try that. Thanks

 

[compnub]

I have the same problem, however my motherboard does not have beep codes. . .

 

[Arobein]

Did you upgrade your CPU recently? I did (Intel P IV 3.2GHz), and know I'm thinking that that was the trouble-maker in my case. My computer is running without crashes for over 3 days now with my old CPU (Intel P IV 2.4GHz. So, I'll be buying new CPU (Intel P IV 2.8-3.2 GHz) in the next few weeks and let you guys now how it goes. And thank you all for your replies.

 

[compnub]

Well i got the computer just last week and its brand new. I also notice with mine that sometimes to turn it on it has to be turned on its side. And sometimes when it turns on the light below "H.D.D" doesn't light up. I'm a complete newbie with PC's so does that mean anything?

 

[halo71]

Why didnt you just take it back if its new and under warranty? Probably voided the warranty now by going in the case.