Very weird problem

[kirillka]

Hello,

Here are my specs:

MB - GIGABYTE GA-965P-DS3 LGA 775 Intel P965 Express ATX
CPU - Intel Core 2 Duo E4300 (1.8Ghz) OVERCLOCKED at 3.0Ghz
RAM - G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
Video - XFX GeForce 7900GS 256MB GDDR3 PCI Express
PSU - FSP Group SAGA+ 400R ATX12V 400W Power Supply (350 W ; 400W PEAK )http://www.newegg.com/Product/...x?Item=N82E16817104953
HDD - Seagate 320GB
1 DVDROM
1 USB PCI 6 slots extender

Computer was working great for more than a year until 2 days ago. Monitor goes blank randomly after 1,2,5,10+ minutes (all fans continue to spin, power lights on) and computer crashes (looks like);-). But sometimes it can work 5 hours normally until it happens. (Usually after it was turned off the whole night). And when it first crashes, the next time after restart the time usually decreases until next time monitor goes blank. It happens not only in Win XP, but during the Win start-up or even when I change settings in BIOS (when I set all to defaults). When Win Xp starts and monitor goes off almost all the times PC crashes, but sometimes it's still operating (I can hear the music/sounds). It's not the monitor problem, because I tried it on another monitor, and the same thing happens.

The temperatures for Video show 53C IDLE/59C under load, for CPU 47C IDLE/ 59C LOAD.
I reinstalled windows, tried to reseat the videocard, removed 1 stick of RAM, nothing helps.

May be it's the PSU problem and not Video card or something lese? It's pretty hot now in NY, so may be it happens because a lot of people use AC, and energy is unstable?
I wonder what can be the problem here?

Thank you.

 

[mpilchfamily]

You link is bad but here is the correct one.
http://www.newegg.com/Product/...x?Item=N82E16817104953

Anyway the PSU is on the light side for the system. It only offers a combined output of 23A on the 12V rails. While the system can run on that you are heavily stressing the PSU and as you know know the PSU isn't able to support that kind of strain for long. So a PSU upgrade would be a good thing. Another 400W unit is fine but it needs to offer about 26A or better on the combined 12V rails.

A good affordable option would be this Antec EA380W.
http://www.newegg.com/Product/...x?Item=N82E16817371005

Yes it offers 20W less the the FSP but it offers a max of 27A on the 12V rails. Plenty of power for your system. You may want to check the drivers as well. It could be a driver issue causing some of the problems.

 

[kirillka]

It offers a combined output of 34A on 12V as I can see from the specs.
It can't be the driver issue, because I reinstalled the windoes xp and the drivers, and it happens sometimes just after the POST screen or in BIOS.

 

[mpilchfamily]

You don't add the amperage rating together to get the total. You'll see that box below the 12V ratings says 276W. Thats the combined output of the 12V rails in wattage. To translate that into amperage we take the watts and divide it by the voltage giving us a combined output of only 23A. He is the screen shot of that label.
http://www.newegg.com/Product/...400R+400W+Power+Supply

No 400W PSU can offer 34A on the 12V rails. 34A times 12V is 408 watts. So there is no way a 400W PSU can give 408W to just the 12V rails. Otherwise where is the power for the 3.3V and 5V rails. You are having power issues due to a 2 year old PSU that isn't able to keep up with the demands of your system anymore. SO pick up a better PSU that offers more amperage on the 12V rails then your current model.