There have been a few annoying problems with my computer recently. When I turn on my computer occasionally it doesn’t boot, it gets stuck at a certain stage in the boot screen. Sometimes certain USB ports do not work. Sometimes components plugged into a USB port that worked when the computer was turned off, then DONT work when the computer is turned back on, no matter what USB port you use.. Sometimes when a USB device is either plugged in, or unplugged from a USB port the computer BSOD’s and crashes. When I click on shut down on my computer, it BSOD’s and crashes occasionally My northbridge fan fell off, could these all be side effects of the chip overheating? At one point when installing a CD drive I didn't realize the power supply was plugged in, and there was a spark when I plugged in the drive, could this have screwed up my motherboard slightly? (This happened about a year ago...) My Power Supply was 20 dollars, could this be because of a crappy power supply?