A couple of weeks ago my PC ran into problems with an overheating CPU. The CPU heat sink and fan had come loose (LGA 775 CPU) from the mobo. I reattached the cooler and all seemed fine.
I decided to replace the cooler as a couple of the fixing posts were worn. The machine now does very little. On power up the lights on the keyboard flash once, the CD drive lights flash on, the PSU, CPU and case fans all spin up but that’s it. No beeps, the monitor does not wake up or show anything and the hard drive does not make any noise.
Any ideas? I have stripped the machine down to the minimum, tried a new PSU, changed the RAM, reset the CMOS (I think anyway – I removed the button battery for a couple of mins).