I recently made a very stupid mistake. I was showing a friend something in my case and i bumped my cpu fan and broke off a blade. i replaced the fan but noticed that it doesn't speed up now. my computer will overheat and shut down it's so bad. I bought a much better heatsink and fan, the problem got better but the fan still won't speed up so under a large load it still heats up. I don't know what else to do to fix this. please some one help.