Just bought a new MB, P4 2.4B processor, memory etc. and fitted it together only for it to fry in a day. Don't really know what went wrong but think it was either dodgy MB or problems with my application of thermal grease. Either way I have returned it and am awaiting a verdict. My problem is that the heat sink appears to be slightly dmaged aon the contact surface due to the heat of the processor. I would sy that the surface is still fairly flat but has fluctuatuions of around 0.1mm (probably less than this as they are impossible to feel). Do I need a new heat sink?? It was really expensive as its one of those Cooler Master silent heat pipe ones. Could I polish the surface again to get rid of the imperfections? If so what do I use bearing in mind that I don't want to make the surface uneven?

polish it with very fine sandpaper and water. Even if you didn't put the heatsink on properly, the cpu should have protected itself from thermal death. it should have just slowed down

Cheers. Found out now that you are right the processor is OK and the MB is the problem. Will take your advice with the sandpaper.