The heatsink assembly fan was very noisy in my HP Pavilion 8563c and I assumed it was going to freeze very soon. I ordered a replacement heatsink assembly. While waiting for the assembly, I removed the left side panel to the computer and placed a 10″ diameter electric fan so that it would cool the unit in case the heatsink assembly froze up. The magnetic field from the fan caused the monitor image to distort so I moved the fan to minimize the distortion. After I replaced the heatsink assembly and re-started the computer the monitor image was blurred. I turned the computer off and checked to make sure all connections were tight and that I had not inadvertently damaged anything — all seemed OK. I was able to access the computer from another computer on the network with no problem — image normal on the network computer monitor. Any ideas on correcting the blurred image? Thanks for your help.