m1730 wont POST

My XPS M1730 will no longer boot. Using the Fn+Power combo i get a slowly blinking capslock button, the others do not light. No matter how hard i look i cannot find what piece of hardware this code points at. I could afford maybe to buy a new cpu or ram but not an out of warranty repair.

Ive disconected everything i can think off (hdd/opticla drive/bluetooth/wifi card etc) and tried each of the 2 ram sticks on their own in both slots. Very very rarely the bios screen will pop up but the progress bar will stick at some point and the machine will lock up before booting.

Any ideas how to procede?

Thanks

Gordy