Computer shuts down when playing game

[VISTREL]

Athlon 64 3200, Gigabyte K8VT800M motherboard
512MB PC2100 RAM
SB Live
Nvidia 6800/Radeon 9800 Pro
Maxtor HDD 40GB
Optical Mouse
400WT PS


Problem: When I play game Operation Flashpoint - computer randomly shuts down. I mean shuts down, not even rebooted. First screen goes black, and several seconds later computer shuts down as if I pressed the power button.

This problem is really bugging me. Sometimes it takes 80+ mins for this problem to occur or sometimes it may happen in first 10 mins.

Here is what I did so far to fix the problem: Changed video card from R9800Pro to Nv6800 - problem persist. Changed Sound card from SB Live to onboard AC97 - still having problem. Changed memory from PC3200 to PC2100 - same problem. Installed numerous mobo drivers, Hyperion 4in1, and AMD64 processor + AGP drivers = NOTHING WORKED SO FAR!

Here is another suprise: I can play all other games like DOOM3 - no problems, can play for hours - STABLE 100%...but when I load Operation Flashpoint - computer shuts down..

Some said that it might be Power Supply, but are you all sure that 3yr old game like Operation Flashopoint requires more power than DOOM3 ?

If I put my Geforce3 ti-200 back instead of those video cards - I will not have computer shut down - everything works like a charm...

I am very confused at this point...Tried playing with BIOS like changing AGP Aperture size, installing BIOS version F5 - nothing seems to be solving my issue..

Ran memtest86 (floppy version) for about 12 hours, did not get any errors...and yes, memory is generic PC2100

IF SOMEONE KNOWS WHATS THE PROBLEM - PLEASE, HELP!

[aAv7]

it doesnt matter how old a game is for your psu to give out-it goes based on how much juice your pc is using. Seeing as you put a lower psu requiring g3 ti-200 into your system and things stay stable, I would assume it IS your power supply. If you are using a 6800nu, your gonna want AT LEAST a 350 watt psu, from a decent company like enermax or antec....dont buy a cheapo cuz you'll end up with the same problem. IMO I say buy a 400 watter...then you have some lee-way.

I know u have a 400 watt now, but what brand is it and how old is it?

[mezkal]

Ultimate's right I'm afraid. The basic thing that makes your PC shut down is that the PSU can't deliver a strong enough signal consistantly enough. When the power fluctuates down the Motherboard and CPU recognise this as a Power Off instruction (the signal goes LOW or ZERO/OFF as opposed to HIGH or 1/ON).

No doubt about it your graphics cards (r9800 and NV6800) both require more power.

Oh and as an addition to what Ultimate17 said make that 400WATTS is AVERAGE POWE R OUTPUT and not just the peak value :)

Cheerrs,

[VISTREL]

Power supply is LinkWorld PowerLink 400WT MAX... I plan on buying Antec true power 450WT or 480..dun remember...I hope that's the problem...

but it's very odd...even when I remove my SB Live it still shuts down..I thought that taking out SB Live would reduce power consumption and give some extra power to PSU...and Geforce3 ti-200 works perfectly cuz It doesnt have power connector so PSU is might be the case...

anyway, if someone esle had this problem and solved it - please help and in about one week Im gonna buy new PSU and will let ya know if it helped.

Thanks :)