Computer with Q9400 Core 2 Quad restarting randomly

[idata]

Hi,

I have built a system a while ago with:MB: GIGABYTE GA-G41M-ES2H LGA 775 Intel G41 HDMI Micro ATX Intel MotherboardCPU: Intel Core 2 Quad Q9400RAM: GSKILL F2-6400CL5D-4GBPQPSU: Corsair CMPSU-550VX OS: Windows 7

Heat Sink: the one that came with the CPU

Computer has been restarting by itself pretty randomly. Even if I turn auto restart off in windows. I have BIOS settings for RAM all set in AUTO.

I tried to run prime95 overnight before, and it was ok, ran video card stability test and it was ok, ran mem test for few hours and it was okay. I have already exchanged MB and PSU. Used core temp to check temperature, and most of the time two of the cores are ~36 degree celsius and the other two are pretty much at 51 degree celsius all the time. I am not sure what the problem was, I have even tried reinstalling windows and it still happens. I have asked GSkill if it was due to RAM settings, and they asked me to test the rams separately. I tried the RAMS separately and computer restarted randomly with either ram. Computer is also protected by firewall and antivirus. Can anyone shine some light on me please? Could this be a CPU problem? THANKS!

[idata]

Hi the first thing to note is that there is something worng with your core temps, if 2 of them are 36 whilst the other 2 are 50, it simply isn't possible as they are so close together. You may want to check the fan integration.

For the restarts, do they happen at any specific point or timeframe? certain programs? is there any pattern at all?

Is it simply restarting or is it BSOD ing?

To be honest it could be any component, although as youhave already cross tested teh motherboard and psu, it is reasonably safe to assume it is not them. It could still be teh CPU, RAM or even HDD.... the only sure way to know would be cross testing

[idata]

Thanks for the reply, I will try to check the CPU fan, but it seems that it should be okay, there is a decent amount of thermal paste on top of the CPU.

Computer restarts very randomly, and no BSOD, just restarts itself.

I have tried running ram test, prime 95 and scan disc... any way I can find out without cross testing?.....

[RGiff]

Check the volts to your RAM it may be low. PSU may not be suppling accurate volts .Had a similar problem with a Rosewell PSU ( cheap unit ) Looked at the ram specs for max volts changed form 1.54 to 1.6 , Problem solved.

[idata]

I tried to set CPU voltage in bios to 1.9v, but it stills shows up as 1.8v, I am wondering if that why.

I ran memest86+ with both rams separately over night and no error found. This is getting very annoying. anyways I can check the hard disc thoroughly so I can confirm it is not a hard disc problem?

[RGiff]

Do you have any program ( software ) on your machine that can show the real volts while running. ??

[idata]

sorry what I meant in my last post was my RAM voltage..... I am using everest, and it shows

cpu core 1.20V

+2.5V 1.92V

+3.3V 3.36V

+5V 5.08V

+12V 12.29V

+5V standby 3.6V

[idata]

the above reply was by me, thanks.

[RGiff]

The 2.5 volts running at 1.92 seems a little off , how old is the power supply ?? If for what ever reason the ram volts drops out of range it can cause a restart.

[idata]

ic, so what should the voltage be for the 2.5v? The power supply was actually < 1yr old. I suspected it was the psu problem so I RMA it, this one that I am using is actaully a brand one one I got from Corsair. I wonder if I should just get another one. I thought Corsair is a pretty reliable brand and that the 550VX was not a bad PSU for waht I have in my system.

[RGiff]

Monitor your volts and see if you get a volt drop right before it restarts??

[RGiff]

A good PSU will keep your volts 99% acurate of what there supose to be . But these are $$$ Silver 80 Plus Cert. or Gold 80 plus cert. Right now I'm using a (seasonic) because it was the best one I could get in the 850 Wat range.

[idata]

Thanks for your attention and quick replies. I was just wondering if I need more power for the system I have. I don't even have a video card and I thought 500W is plenty.

Actaully, I tried to use another PSU before, I think it was a 400W, and it was actaully ok, so I RMA the corsair PSU, when I got the new PSU, installed it and computer ran normally for a few months. I left the machine on most of the time, too. But recently, sometime before I started this post, it started rebooting again. So I totally don't understand why. Only thing was I installed cute PDF before it started rebooting again, but I doubt that's the problem?

[idata]

It's been a while, it seems that my problem has been solve by changing the power supply, I took out the Cosair and put in an OCZ with lower power, and there was no problem from then on. I used the Cosair in another system, and there was not problem either.... so what all these headache, I wonder why... I thought Cosair is a good brand.