Computer erraticly shutting down durring POST

[Sausagemonk]

I've had my machine for a few months now, and it started shutting down while in windows and restarting. This would happen after the machine was on for hours at a time (usually when I was at work).

Now if I do so much as plug the machine into the wall, it will turn on and immediately reboot, before it even has a chance to POST usually.

I tried replacing the motherboard and power supply so far, and removed the RAM to see if that was the problem. Exchanging the motherboard fixed the problem for a couple of days, and now its back to the same old problem. I'm thinking now I have a problem with my processor, but it never was overheating before, even when the computer restarted.

My specs are:
Asus A8N SLi Delux motherboard (brand new, just replaced)
Athlon64 3000+
1GB ram (forget the brand)
Geforce 6800
300GB Western Digital
200GB Maxtor
Creative Audigy 2
Antec 350watt PSU (brand new, just replaced)

 

[wozelbeak]

Can You Tell What Temp It Is Running At?
AND I WOULD HAVE GOT A BIT MORE WATT IN YOUR PSU IF I HAD CHANGED IT 450W.
Woz

 

[Kage]

Hmm, I'd still suggest the PSU, and like Wozelbeak says, yuou should have got about 450watts. You computer seems too powerful for a 350watt, and wouldn't push it.

350 watt is way too small for the graphics card, etc.

I'd replace it again and try again. If you keep running with that PSU, its possible that your computer could be damaged by spikes in the power, etc, and may already be happening.

Basically shut off now, and replace.

 

[Sausagemonk]

It usually ran around 38 C, which was what my old Athlon ran at for a good two years and I never had a problem.

Also YES, I know 350 is a bit small, but I knew this PSU worked, which is why I swapped it out.

I should also note my old PSU was 450 and I was having the same exact problem.

 

[Kage]

Well maybe that was a bit faulty anyway.

But since changing, you've done it worse...

You should never go from a higher wattage PSU, and then drop it. Thats just going to kill it.

If you had a 450 watt to start with, I would probably have gonr with a 500watt and got a good make.

Theres a chance you could have damaged your PC now. If your computer isn't even making it past POST, something is seriously wrong.

I'd take that 350 watt one back, get a 500watt, and test that.

If you changed your power supply before it wouldn't POST, this is definietly the problem as the 350watt is probably too small to even start that system up.

I hope this helps.

 

[Sausagemonk]

I very highly doubt I damaged anything, since I was attempting to boot the PC with only the motherboard, processor, ram and video card plugged in. I plan on getting a 500 (or 550) later today and see what that does.

I don't have an extra 939 processor to test, so if the PSU is not the issue... could it be related to that?

 

[Kage]

Its possible the processor could have gone, but lets worry about that when it comes.

First try setting up that new PSU, and we'll see if it boots up any further.

 

[wozelbeak]

you know what, i reckon you are getting overheating problems. undo heatsink and fan and see if there is any thermal paste/grease/tape on it.
is your heatsink sitting correctly on your cpu? because i once put the fan and heatsink on crooked and had the exact same problem. have a look and see.
woz

 

[lhuser]

Your Power Supply doesn't bring enough jucie for the comp. Go with a 500W

 

[Sausagemonk]

Just bought a 480watt Antec PSU for about $100 and still the same thing.... The only thing left to replace now is the processor I suppose...

Also yes, I have checked and double checked that my processor has thermal paste, and it is applied correctly, and the heatsink is sitting on top correctly also. The computer is not on long enough to overheat, and it is in a cool place, so it is not hot to begin with either.