Recently out of the blue, my PC started making a loud sound (sort of sounds like a loud buzz or whirring). I thought that maybe one of the case fans had built dust up so I clean the inside of the PC with air duster, and vacuum. The sound went away for a week and then came back again. I tried cleaning again and to no avail. If I hit the top of the PC lightly, the sound kind of smoothes out but then comes back. I'm not sure what fan it is.
ANy ideas?
ANy ideas?