I am facing a big problem with my friends CPU. So I decided that I must share it with you all. What has happened was that a few days ago I had brought a CPU from my friends home and I was asked to reinstall the xp operating system. So I thought the process may be very simple but it turned to be otherwise. When I started the system it refused to turn on. So I removed the entire cabinet and then I thought I will have to do some repair work. What I observed inside is that the fan is rotating only the half way. While the light of the hdd and the other drives are turning on/off at regular intervals. So what can be the problem here. I think there might be some problem with my psu. How can I get to know whether my psu is working properly or not. Please do answer my queries.