PC Problem with Picture

Yesterday I installed a Gigabyte Rocket 3D Pro sumthing cooler on my brothers P4 2.8 computer which works pretty well. But today I found that whenever an application like a game or 3D Mark 03 is opened (while the pc is still loading) the pc reboots itself. When it hits windows again it says sumthing about a fatal error. So from there I thought maybe a corrupt HDD or PSU. I had a utility installed called PC Mechanic 5, So I ran the program (luckily the pc didnt reboot) and I started using the options on the program to clean junk files, fix errors, clean registry etc. After all that it had a degrag option, so it started running ( The Defrag took about +-2Hrs) and when I arrived back at the pc, the screen was blank. The monitor was still on but no picture, I tried everything I could and eventually turned off the pc. When trying to turn it back on, it still doesnt give a picture on the screen.

What could be wrong? Could it be that the HDD is now damaged and cannot load ?? Maybe the PSU damaged ??

[DanTheBanjoman]

Sound like you didn't install the cooler right, might be a heat problem since the computer reboots under load.

no its not a heat problem and im pretty sure about that, because I opened the temp monitor while it was defragging the pc and the temp went up to 63 degrees celsuis and it didnt reboot so that rules out temp problems.

Any Other Ideas????
P.S> When the pc rebooted (when trying to run games) I checked temp immediately in bios and temp was +-54 degrees, which then means it cant be a heat problem.

[DREXY]

have you tried to reinstal your os

[DanTheBanjoman]

Reïnstalling the OS would rule out software problems. If you have a spare harddrive to try it on it's not a bad idea.

I havent tried to re-install the OS as I have no idea how to do this with a Pitch Black screen on my pc ?? Remember, I cant even see bios...

I made sure the gfx card was seated correctly, and I also checked all the ram modules aswell as slots, problem still persists!

Could this be a power problem ? The pc has a 300W PSU. Its a P4 2.8Ghz LGA775(prescott), Radeon 9600PRO 256MB, Gigabyte mobo, 80Gb HDD, 1024 400DDR Ram.

Btw, when I was trying different ram stick + slots I had to turn on/off pc couple times while changing around slots etc. but I noticed now that whenever I push the Power on button pc comes on(still with black screen) but when I push the button again for Power OFF the pc doesnt turn off???? What is up with that? When I want the pc off, I have to turn the power off @ the wall!!

[DREXY]

it is not os or hdd definitly.
your power seam ok ( its starting but without picture)
it could be 9600, try to test it @ yours pc, it's a best way to be sure.
check the mobo manual,some mobo's have four checking diode's,they can tell you if something is wrong with it (they usualy come separatly and you have to conect them).

If I have time maybe tomorrow I will try swap gfx card + HDD and see if anything changes. Are you sure its not the power because in the beginning applications were just rebooting the pc (apps that suck alot of power).

[DREXY]

it could be power, but you are starting pc now, but whitout picture?!
you can easy test it, try to eject cd-rom (while the power is on).
I can be sure only if I'm there to see what's wrong.

CD-Rom doesnt open and power (turn off) button doesnt work! HELP!!

[DREXY]

I'm sory to inform you, but your power is probably fryed.
It hapends. Just be carefull when replace it, if your mobo is fryed you can fry and new one! but it's not so often.