So, a mate of mine has a PC that he uses for video rendering.................quite a stressful operation for a lot of PCs?

He buys an AMD Athlon II X2 270 to speed it up and finds that this doesn't work (like black screen?)...............

He moves a working processor into it, to see if it is the processor or the PC that has the problem, and that doesn't work, so he puts the processor back into the machine it came from.................and it doesn't work there now.

A very unfortunate case of timing I would suggest?..................the PSU has become a killer.

The moral is: DO NOT BUY CHEAP POWER SUPPLY UNITS.

Please give that statement a thought?.................the PSU interacts with all the PC components, and can kill the lot! and even yourself, when it sets fire to your home!!!

At a VERY MINIMUM you want power surge protection, high voltage protection, and low voltage protection.

A good quality MoBo will also help ................and you buy those on specification not name!