About to throw pc out window....!!

[c0nfused]

Hello guys.(long post sorry)
Hope maybe someone here can help me im totally lost on this....
Bought a pc at xmas:

Gigabyte ga-k8n-sli mobo
Athlon64 3500 cpu
One gig ddr ram
windows xp
sata2 hdd, 2 dvd drives 500w psu

Anyways it ran fine till 3 months ago and then randomly started to switch off, I mucked around and eventually did a reformat, problem solved..

Untill now, the system is stable for using the web, cd burning etc. However within a few mins of starting a game it almost always switches off, with the exeption that now when i try to reinstall windows it always switches off just before or at the create/delete partition screen.
I have tried almost everything suspecting the ram, overheating, drivers, bios, psu etc

[thepassenger]

Did you buy a complete new PC or the components?

If it's a complete PC, ring them up and ask for a warantty repair.

If you've cleaned out all the fans and such, then I'm going to have to give the PSU an evil eye.

[c0nfused]

It was a home build. The psu is a Colorsit 500w.

[thepassenger]

Ok. Open the side panel up and have a poke around, any sign of scorch marks? Blown or buldging/leaking capacitors... perhaps a smell of burnt electronics and plastic somewhere?

Touch the heatsink is it hot or cool after the system has restarted?

Are all the fans (specifically the CPU) working and spinning freely? If one is sticking or having trouble try unplugging it if it's hooked in to the motherboard (obviously if it's the CPU fan don't unplug it), did that help?

Also do the same with the graphics card, is it getting really toasty, are it's fan(s) spinning, etc?

If the heat sink is warmsish (not burning hot and not room temp after a few min of operation), the fans are spinning fine, the gfx card and mobo show no damaged capacitors and no other untoward things appear... I'm still going to be looking at that PSU as suspect.

[Frederick]

sounds stupid but you have plugged the little 4-pin power plug from the psu into the motherboard haven't you? if you just use the atx connector it will supply enough power to run but not for heavy going...

[annodomini2]

Its overheating and switching off, get the temperature monitor software for your pc and the free version of 3dmark or equivalent and run one of the short tests, check the temperatures afterwards (assuming it runs ok).

Possibly as has been said clogged/stuck fans, or it could be a blown cap.

But I'd recommend getting an extra case fan and ensure there's plenty of space around the machine for the case to breath!

If you have more than one hard drive, get some coolers that bolt to the bottom (space allowing!), a few quid each but make a big difference.

[sp60]

Two more things to add, try reseating the memory, or removing one of the sticks to see if that improves the situation. Also try adjusting the settings in the bios to reduce the clock speed of the processor and memory. This should allow you to succesfully install the OS if you are still having problems getting it installed.
Oh...and check that the heatsink compound is ok between processor and heatsink.

[Plotloss]

My guess would be that there is a buildup of dust between the CPU fan and the top of the heatsink.

[RichUK]

I had a similiar problem with my PC at home. Was solved by adding an extra fan over the processor.

Temps went from 60 deg+ down to 45-50.

[big_treacle]

Do you have decent RAM? I had a problem with a machine where I'd bought memory with the right spec for my motherboard. I had the BIOS setup with all the correct bus speed and memory settings. But often under heavy load I'd just get a reboot with no warning. No overheating problems, no faults when running memory test software. NO NOTHING.

Did some more investigation and it turned out that it was a problem with the chipset I had & certain brands of memory running at that clockspeed. Spent a few quid on some new memory - of exactly the same spec - from a better brand (corsair of someone i think) and all problems solved.

Also, I guess it's worth checking all the memory settings in your BIOS are correct.

Also also - you haven't plugged some new thing in that's sucking power? low power i would presume might give the same results.

[Wildfire]

What Graphics card are you running? Some require you plug extra power into them, either via a molex or floppy adapter.

Does sound like a heat issue though. Run Ultimate Boot CD, test your CPU, HDDs and RAM, then boot into the BIOS and leave the computer running with the temp monitor going and see how hot it gets.

Clean out the whole system of dust. And check to see if your exhaust fans are working.

[polus]

Is there a temperature monitor in the BIOS which is swtiching the PC off? I would think so.

I had this problem on my computer. I turned off the restart at X temp in the bios. It was then freezing when the heat was too much but I didnt know which component it was so went around each IC spraying freezer spray at it until I determined that it was a regulator inside the powersupply. After cleaning the PSU out and moving the cabling so there was better airflow I havent had a problem since. Freezer spray can be very useful when ICs overheat and can be bought from RS,Farnel or Maplins.

I would suggest going over the internals with the vacume cleaner anyway as the build-up of dust doesnt help.

[c0nfused]

Thanks for all the fantastic replys guys.
Problem sorted I think
I tried a few of the suggestions. However I removed the cpu heatsink to remove the dust, I cleaned with TIM and put some compound in and hey presto.(thanx 60)
Bf2 working solid on max setting.
I think the cpu couldnt have been in contact with the heatsink, and overheating must have triggerd shutdown, i think.
anyways i'll see how it goes....