Computer Restarts without any error

[Smoothy]

Hello people,
A few weeks ago I had an overheating problem with CPU(Pentium D 3.4 Ghz). The temp was like 110C, working a few minutes and than restarting. I knew its CPU problem so I changed it, bought a new Intel Core 2 Duo E8400.
Now this one is working good (temp. 35-42C) but the problem is that after around 8 hours of working it keeps restarting again and the temps are still cool (35-42C).

I made some tests, formated disk and installed a new copy of windows, switched the RAMs in different slots, replaced with different one, stoped the "Automatically Restart" option of windows and still the same problem.
Does anyone know how to fix this ?

Running:

Asus P5B-Deluxe motherboard
Intel Core 2 Duo E8400 3.0GHz cpu
3x1GB Corsair XMS2 DDR2 800MHz 1.9v memory
GeForce 6600 graphic card
ASUS Triton 77 92mm CPU Cooler
RaptoxX 550W power supply
Samsung 250GB hard disk
and 2x512MB Kingston memory for testing.

 

[mailpup]

Your power supply might be the problem. Do you have access to another to test?

 

[Smoothy]

As a matter of fact, I don't :S, Is there any other way to test this ? Any program or something to check the stability or something like that ?

 

[Kcircyrd]

You can buy a hard drive tester for $15 to $25... Or a replacement power supply for $55.

But the problem could be anything. Usually power supplies do not cause the restart problem... that is more often the video graphics card. Next choice is overheating of the CPU from bad thermal paste application, or bad CPU fan.
When you cancelled the automatic restart option, did you not get any error messages.
Some low cost maintenance: remove and replace the thermal paste on the CPU remembering that too much is as problematic as too little.
How old is your system. Your power supply and video graphics card look like weak points...
Memory should be fine since you have run tests... but if you have not run MemTest86 free version on each memory module for four hours or 7 passes, that is your next step... as you must rule out memory modules before replacing power supplies or video graphics cards.

 

[Smoothy]

My system is like 3 years old but I have changed a lot of hardware like hard disk, CPU, RAM and Cooler. I didn't get any error message with the automatic restart option, I never got any error message only about a year a got I was getting BSOD and I changed the HDD (fixed the problem).

The problems :
1.Video Graphics Card overheating

I'm using speedfan and the temp is always low or ok never gets high.. I know its a weak graphic card nowadays but I don't think that it is making troubles..

2.CPU overheating

As I mentioned I have only a week running with the new E8400 which looks pretty cool while looking on speedfan frequently it didn't get high temp till now.. I'm sure its not CPU problem.

3.RAM memory

I know I should run MemTest86 for insurance but as I wrote before I tested with 5 different RAM memories so there isn't any chance that they all contain errors.

4.Power Supply

As I saw until know my Power Supply is a cheap product so it may cause troubles, it is old around 2 years and the thing that makes me doubt is that it is making a creepy sound like " ssssssssss ", I checked it a bit, and its not the cooler problem but something deep inside.
I was looking for voltage, the bios tells me this :
VCore Voltage 1.264V
3.3V Voltage 3.248V
5V Voltage 5.120V
12V 12.038V
I have some other power supplies in other computers of my family maybe they can do for some tests but they are smaller than mine.. Mine is 550W and one of them is 240W.. how do I calculate how much W do I need ?

What else can cause the restarting ?

Thnx so much for response.

 

[Kcircyrd]

I am left with the belief that the problem is in your power supply after all... We have never seen or used a RaptorxX, but I don't find any test results on line either.
Power supplies can suffer from dips and surges that impact on a quality system.
It is best if you can test them on an ocilloscope, but in lieu of that. I would want a Corsair, Zalman, OCZ, PC Power and Cooling, Sparkle, or FSP group. I would avoid Antec, Coolermaster, and Thermaltake due to inconsistencies we have found from model to model.
There are plenty of reviews on power supplies, and a very good post on TechSpot which evaluates large numbers of them... as well as available from a gurgle search.
Look for one heavy in weight, and FCC approved.
You have tried everything else and the usualy suspects check out fine on your install.

Please keep us informed.