when you say your computer turns blank, can you be more specific? Does it turn off or does it still run but your monitor displays nothing? If it is shutting off, the problem is most likely the PSU or motherboard.
use CPU-Z to get your real time CPU speed and multiplier information:
Check your BIOS setting for “cool and quiet” if it is turned off, your CPU multiplier will not drop from the default speed
Oh the display shows nothing, oops sorry about that. wow you saved my life. cool n quiet was turned off and i turned it on now its all good. i guess its my PSU dying because if i turn of cool n quiet the processor will get really hot and the computer will just lock itself up.