|The CPU won't get very warm if it has hardly any work to do (eg Windows not running and no applications running), so that doesn't necessarily indicate a CPU problem.|
If monitor says "no signal" it could mean the graphics adapter has died and needs replacing.
Also, the hard drive may have failed. Test it to confirm. Use SeaTools for DOS.
On a working PC, download SeaTools for DOS from here: http://www.seagate.com/support/down...
Now install IMGBurn from here and with it create a CD from the SeaTools ISO file:
Boot your faulty PC from that CD and SeaTools will open (may take a few minutes).
You may have to go into BIOS Setup as set the CD drive as the first boot device if the PC doesn't boot from it.
The graphics adapter & hard drive may well be okay but testing them is all a necessary part of the troubleshooting process, otherwise you will get nowhere fast.