PC randomly falls off, need help.

[TomZion]

Hello,

Im having a very strange problem with my computer, and I hope someone can help me with it.

My PC just randomly falls out. No, not resetting.. it falls completly OFF and after like 5 seconds it turns on again. Sometime it takes like 2/3 minuts before it goes on again. In that case I have to put my PSU on/off many times before it wants to get on again. This problem happends very randomly: Sometimes only once in the week, sometimes 10 times within an hour. My computer is nearly two years old now, and this problem occures for like 4 months now.

I also have some small problems that have happened for only 2/3 times, but maybe this information helps for the ''main'' problem: There were some erros about a memory failure (intern RAM) when I tried to close down a game. There have also been a problem with my harddisk when I just stared up my PC. It had to restore/repair some files on my harddisk before it could start up Windows.

What is NOT the problem?
- Software (Im quite sure software can completely shut down a PC)
- Memory (tested it already)
- GPU (Dont think that this is the problem)
- Heat (no hardware piece gets warm at all)

What have I done so far?
- Re-assembled the hardware pieces, checked all the cabled and connections)
- Cleaned my PC from dust
- Ran memtest86
- Read alot dutch articles about similar problems, no solutions.
- Checked my motherboard for dead capacitors. Found nothing.
- Stress tested my GPU and CPU. My computer didnt fell off during this.

Myself, I think that either the motherboard or the PSU is the problem. But since I cannot get a spare PSU I cannot be totally sure. Thats why I started this topic. I hope someone can help me.

Im also thinking about upgrading my PC, so that I hopefuly can get ride of the problems. The only downside on this is that if something else inside my computer is the problem I will still have the same frustration but with other components :/
New cpu, ram, motherboard.
AMD Athlon X4 620
4GB DDR3 ram Kingston
Gigabyte GA-MA785GT-UD3H motherboard
My budget is +/- 250 euros (lets say 300 dollar). I guess its a good choice?

Thanks for reading this,
Greets Tom.

My current specs:
Intel E6750
Asus HD3870
3GB ram Kingston
PSU: Corsair 520Watt HX520W
Motherboard: Gigabyte GA-P35C-DS3R

PS: Sorry for wrong spelled words and sentences. And if I started this topic in the wrong section of the forum im also sorry about that. New guy here.

 

[gomi]

Usually the culprit is the cpu, have you updated the bios? My bro tried to install an OEM version of vista that screwed his bios so he was getting all these weird mobo problems but he updated the bios and that seemed to fix his problem.

 

[welshmousepk]

i had a very similar issue a while back.

download speedfan or cpuz, and check oyur temps to see what your mobo sensors are reporting. i know none of your hardware is actually getting hot, but in my case it turned out the heat sensors were broken, and reporting temps above 90c, causing my pc to shut itself of in panic.

have a look to see what your temps are under load, and when it crashes. it may well be the same isse

 

[TomZion]

Thanks for the reactions so far. Im 100% sure that it is not a heat problem. Im checking the temperature quite alot and havent found anything strange so far. My PC also can shut itself down when it hasnt been on for more then 20 seconds. In that case it never can be a heat problem.

I also do have an OEM version of Vista installed, altho I have installed that on day 1 when I had my computer. The problems im having are occurring for about 4 months now. So I doubt if the BIOS is the problem.

 

[TomZion]

Nobody that has got a clue?

 

[Scotteq]

Do you have access to a known good Power Supply? That's the first place to check if/when you're having issues with the computer randomly shutting off.

 

[TomZion]

Well that is kinda the problem since I have not I really did my best finding one but I havent really got much friends who are into computers.