Resolved PC keeps shutting down

i recently built a a PC
its specs are as follows:
OS: win 7 64 bit
mobo: asus M4A79T deluxe mobo
RAM:OCZ 4 gb ddr3 pc3 12800
CPU: AMD Phemon 2 X4 955
GFX Card: nvidia GeForce GTX 260
PSU: colorsit 500W model:500u
please note are all previously used components!

as i was installing the OS it suddenly shut down i noticed the heatsink was was extremely hot cpu fan was not spinning so i ensured all pins were making full contact that seems to have so it, when the operating was installed i got a post message reading "overclocking failed press f1 to reset to default ", which i did and everything seems to work ok, until 2 days ago the PC started shutting down after 10mins operation so far it has happened twice

does anyone any thoughts on what is happening?

 

You could have a overheating problem, you can download CoreTemp a very simple free program to check.

http://download.cnet.com/Core-Temp/3000-2094_4-10794077.html

 

yes i have used thermal paste and core temp dosen't record or show temperatures

 

CoreTemp, should show you your temp at the bottom end of the little screen.
You could also try CPUZHW from here:

http://www.cpuid.com/softwares/hwmonitor.html

 

i dont know why it does not, i'm using it on my main PC which what i'm on now, i've uninstall it and reinstalled it but for some reason its just showing the load percentage, but i'll try the |HW monitor let you know what it reading it gives out later on

 

HW monitor gives no temp readings either

 

In this case I would be tempted to say, that something on your Motherboard is not functioning as it should.
If it was me I would re-seat the CPU and HSF and make sure it is seated correctly and the fan working, also make sure that the CPU is registering correctly in the BIOS, since you must have had it on a overclocked setting to start with.

 

I was going to suggest resetting the BIOS but I agree with Arie and check for a new BIOS version. Installing that should reset the BIOS in the process.

 

i'm on it at the moment, when i can get it installed, i will i'm also trying from a friends suggestion AMD overdrive to auto set the Ram timings as he thinks that could be a problem as the M4A79T mobo is a very finicky piece of equipment i will post the results when i'm done





so far the AMD overdrive seems too have stabled the memory as i have had no crashes tonight, tomorrow will try 3D accelerated games to be sure but looking good so far keeping fingers, and i'll be damned if i can figure out how get the bios updated

 

i've finally cracked it, after god knows how many hours, it was the RAM timings just slightly out, i have now corrected them and and no more BSODs

thanks too every one for their help most appreciated