No display

Good day, I have a problem with my PC it always stop "hang-up"/reboot "sometimes with blue screen". I already reinstall the OS to remove if there is virus causing this problem. I also check my hard drive for bad sectors and I found out that my hard drive was in good condition. I also check if my memory and video card but they are both working. is there any problem with my processor or board? I try to disassemble my processor to clean its fan but it turn out that there is no display any more when I test again my PC, here is the specs of my PC (Intel Celeron D 2.4Ghz, Asus Motherboard, 1G DDR 400 Memory and 80G Seagate baracuda) thanks and more power...