Now i thought I knew a thing or too but im stuck now. My sisters computer went tits up when she got some sort of error, so just turned it off at the power! the thing now turns on, but nothing appears on the screen, ive tested most things using an old computer i have, and figured that the CPU needed replacing. shes got a P3 450, so i got hold of another one of them. Just fitted that today & it still doesnt work, but when i put a pentium 2 CPU out of my older computer into it, it works fine. (her motherboard supports slot 1 P2 & P3) Now i guess both the P3 processors I now have could both be broken, but im pretty sure the one i just got should work, although i have no other machine to test it on. anyone know whether the motherboard in her computer could have broken in some way, meaning that it will only run P2 CPUs now? i didnt think that was likely but cant think of an explanation. i have been told it could be the voltage regulator something! can this be fixed. its a daewoo cb648x-bx mtherboard by the way, and intel pentium 3 450mhz processor. if anyone could help id very much appreciate it.