|Please detail what and how you cleaned it. This is very important.|
Was it unplugged? <important>
Did you use compressed air (or gas)? <good>
Did you use a vacuum of any type? <bad>
Did you remove anything including plugs, cards, heat sinks, boards, drives, etc.?
What exactly if anything was removed and how?
Did you ground yourself before touching anything inside of open case?
The more complete your answers are, the better we can help you with this.
You have to be a little bit crazy to keep you from going insane.