Asus P5N-E SLI
Intel Quad Core Processor 4x2.4
Samuri Cooler
4 Gigabytes Corsair 533 Ram
XFX Geforce 8800 GTX 768mb Ram PCI-E
500Watt PSU
Samsung 160 Sata HD
Thermaltake Shark Case
Fujitsu Siemens 22" Monitor
Computer has ran perfectly for approx eleven months.
Started to get error on startup "Something has altered your processor settings".
Then after about two weeks switch on : The Board has power : All fans are running including
PSU fan.
However I get no signal to the monitor at all, no beeps.
I took my graphics card back to shop, tested Ok.
I have tested PSU on other computer with a 6600 AGP card : worked fine.
Tested Ram on friends computer : worked fine.
I have reset heatsink.
Can any one help.

You may need to manually reset BIOS on the board - Unplug the power, take out the battery on the motherboard, and move the jumper. Leave it like that for a few minutes then put back the jumper, battery and power.
Look through the manual for jumper location (If relevant to the board).