I just replace my brothers 1Ghz Duron with my 1.2Ghz Thunderbird, and the system won't boot , or initiate the graphics card now, even when going back to the Duron chip, I've checked the chip and graphics card, which is a Leadtek 64mb Geforce 2 ti200, on another computer and they work fine, all the system and hsf are runnning, so it can't be a power issue, there's no beeping to suggest that either the ram or graphics card aren't correctly seated, so what could the problem be, the bios is on jumperless settings, I was wondering whether it's stuck on a setting of some sort, and isn't supplying enough power now to get the cpu going, the cpu doesn't show any signs of damage to suggest core crush. I'd appreciate your time😕