About 6 mos ago I built a machine with the following components:
AMD x2 4200
Case: Antec P180
Sound Blaster Xi FI
1 Sata HD
Mobo: ASUS A8n-SLI Deluxe
Things worked great until about a month ago. STarted getting random reboots and freezes. Reinstalled drivers. Reboots progressively got more frequent. Two nights ago shutoff and would not restart. I would hit the power and for about a second the fan would spin then shutoff. Took hardware out piece by piece. Found out the Vid Card was the issue. If the card was out the system started no problem. If it was in, I would get the one second then shutoff problem. I put in my old vid card. A Geoforce 5200 and things work fine, have had no reboots since. Obviously I want to use the 7800 rather than the 5200. Does this sound like the 7800 is fried? If not, what else could it be. Would like to know before I drop money on a new card. Thanks a lot.
It actually may be the PSU going. I haven't heard much of video cards slowly dieing but we all know PSU's do it all the time. Try disconnecting everything except your video card and boot HDD and see if it will post.
Well...I tried removing my hardware and it still did the one second power than off thing. I decided I would gamble on the PS. The bad news is that the same thing happened, the good news is I have a 550 watt PS now instead of 480...lol. Anyway, I am assuming now it must be the Vid Card (maybe got too hot and fried? I don't know...) since everything else is working now. ANything else at all you guys could think of? Or are you betting on the vid card too? Unfortunately I don't have anyone I could test the card on their system.
get a power supply tester(tigerdirect.com) and if you see any missing leds for volt's that shouldnt be there and/or if it gives a long beep then it is psu. it sounds like maybe a bad vid from purchase due to the replacement of it allowing for POST. there are other options from here, please post conditions after.
I will get a PSU tester and test the PSU. Was playing a game before and my system rebooted using my old vid card too. (1st time that has happened). Now maybe because the card is old and I was pushing it a little is the reason this happened, but it seems like an odd coincidence. I will take note if this happens again. Could the mobo be partially shot? I forgot to mention before, when my system was rebooting all the time, once Windows restarted I got a message saying there was a problem with one of my drivers but it didn't know which one. I updated all my drivers after that. Not sure if that is relevant or not. Also, this may sound ridiculous, but I live in an old apartment. Not sure how much juice is flowing out of the wall, but I was wondering if I am suddenly not getting enough to run the computer completely. I don't think it is this, becasue I have run it from the same socket for 6 mos. I will try another socket just to be safe.
in order to rule out faulty wiring in your building get a ups. then download untlimate boot cd from the same name web site. boot from that cd and runa burn in overnight which will take the os out of the equation. also get memtest 86+(memtest.org) and run overnight which will rule out the memory. overclocking can damage your hardware so that may be the cause. you might also try a bootcd to test the hd. if you have ghost you can image your current os and reinstall the os. then without installing any drivers run cpuburnin(download.com) and loop a series of movies from your hd with a media player overnight.
u might consider getting 3dmark benchmark to stress the vid and see if there are more errors there. since you have a good old vid card the mobo may be damaged and microscope bootcd might detect it.please post the error messages speciffically here.
best of luck.