This has me stumped.
Desktop PC single Processor AMD Phenom, clean and no dust, air cooled, with 8GB Ram DDR2 and Win7.
This switches off randomly, just as if it has a heat issue. All heat sensors are connected and hardware probes show that there is no unusual rise in temperature at the time of shut off. Sometimes shut off happens at boot, sometime after 10 minutes idle time, sometimes after 1 hour of constant use.
This has been scanned for Virus and Rootkits and is clean.
Symptoms are the same every time, no blue screen, no freeze, no warning of any kind. Just power off. The only difference here can be that 4 out of 10 times you cannot power back on with the switch, you have to switch power supply off and on again.
The PC runs forever in BIOS mode, e.g. booting into BIOS only. It also seems to 'behave' in Safe Mode. But it does not in Windows.
I have completely reinstalled Windows after full HDD format and the problem still persists. So it is not a rogue driver that has crept in or some 3rd party software.
As I said, the symptoms are like overheating but it is not, it does not appear to be a driver issue, so it must be hardware and standard windows function combined, but I don't know where to start diagnosing this.
Anyone any ideas what to do next?