PC Problem. Please help.

[golwg]

Went to see my brother today and he has an HP PC that is just out of warranty!!!

Anyway, it sometimes starts but then the pc shuts down completely.

Tried to do a recovery of the system but it starts and then a few seconds later it shuts down!

Anyway, checked the ram by putting it in different slots......Still the same
Checked PSU with PSU tester.......No faults but still the same issue
Removed heatsink and made sure CPU fitted etc..........Still the same
Checked all cables..........Still the same
The CPU fan comes on briefly and then goes off. Sometimes it stays on but nothing on the screen.
Monitor works fine
Checked through bios......Still the same

All i can think of now is that the motherboard is faulty.

Anyone else able to help

PC is an HP a6000 with an MCP61PM-HM, 2GIG DDR2 RAM, amd 2.2 AM2 CPU

[golwg]

All sorted now. It was a dodgy CPU!