After I switched the power off from the back of PC to force shutdown the PC due to it freeze, the PC could not bootup again. When I powered it on, the fans runnng, all of the lits on, the CD lit on, the CPU heats up, and Hard Drive spinning, but No beep, no bios, and its blank screen. I played with RAMs randomly in different slots, replaced the video card on AGB slot. The Motherboard just don't react whatever I do. One thing, the small fan on the top of heatsink was not functional nomally, it spins very slow. Anyone has idea what could be the problem? Your input would be appreciated.