Urgent help needed with my mobo!

[Highlex]

Hello guys, i'm having a very serious problem with my ASRock 775Dual-VSTA motherboard.

Lately, my computer has randomly been shutting down all by itself, everything to do with the motherboard looses all power, my moniter stays on but looses signal.

I thought it was my powersupply so I got a differant one and the problem still persists.

I've had the mother-board for about a year with no problems at all and now it powers off randomly. The problem is so bad I can't even get to the windows logon screen without it loosing all power!

I'm running a Thermaltake 430w, 2GB of DD2 Ram(667?), 160 GB Sata Harddrive, intel pentium 920 d (2.8ghz dual core), with a 7900 GT KO Nvidea Video card!

It seems if I unplug the 4-point power cable that powers the USB section of the mother board (see picture)

http://img337.imageshack.us/my.php?image=powerwc7.png

But leave the main power plugged in the the computer stays on but of coarse doesn't function properly.

Can you guys please tell me why my mother board is randomly loosing power?
-Thanks in advance AnandTech!

 

[Zap]

That 4 pin plug is to power the CPU, not the USB.

One possibility is that the motherboard is failing.

Another possibility is the power supply is failing or insufficient. Is the Thermaltake 430W (TR430?) your original, the replacement or both? That power supply is actually not very powerful as IIRC it only puts out 18A for +12v, which your processor and video card both use quite a bit of. As a comparison, an Antec EarthWatts 430W power supply can put out 30A on the +12v, quite a bit of difference.

 

[Highlex]

Thanks for the reply, oh okay so the 4 pin is for the CPU... cool! Atleast I learned something.

The powersupply is the one i've always used and it worked perfectly fine for over a year untill now. I tried two powersupplys already and both of them give me the same problem so I don't think it's the PSU.

Could it be a lack of thermal paste on my cpu / cpu fan heatsink thing. Because last time I lifted the fan off to dust it there was barely any thermal paste.

Could the cpu be heating up so fast it shuts down the computer as a precaution? But can a cpu reach skecthy temperatures in 10 seconds?

 

[nomagic]

You didn't clean and reapply thermal paste? That is not good practice. Thermal paste fills the small gaps between heatsink and IHS. These gaps unfilled can trap heat and interfere with heat transfer.

As to your question of system shutting down immediately after startup due to high temperature, it is entirely possible. Modern processors have thermal control circuits which monitor temperature reported by sensors. At certain temperature, the circuit is activated and and the processor would throttle to reduce heat. If the temperature continues to rise, thermal shutdown is initiated.

 

[Highlex]

I didn't know what thermal paste was (first time lifting a CPU fan unit) and I figured it's susposed to be there so I left it alone but there didn't seem to be alot of it and I didn't have any thermal paste to add to it.

But my computer barely turns on for 10 seconds, and when the cpu is unplugged it stay on forever. Hmm, I guess i'll start with taking out the motherboards battery to reset the bios, adding adequate thermal paste and then starting it up with only the bare minimum and seeing how long it runs for.

 

[Highlex]

I fixed it! All I did was remove my motherboard battery for about one minute and applied new thermal paste! Im typing this message on my computer right now! So everything is good... for now!

 

[Drsignguy]

Originally posted by: Highlex
I fixed it! All I did was remove my motherboard battery for about one minute and applied new thermal paste! Im typing this message on my computer right now! So everything is good... for now!

You should be reading THIS thread. Not to learn about over clocking, but to learn other aspects of your computer. In there it has a location to properly apply the TIM ( thermal paste ). Also, there are links to temp programs to monitor your Cpu temps among other great information needed. Take your time reading it. You just may learn something, I would suggest that you do...