The fan on my nvidia 8600GT was coming into contact with the fan casing and making a really bad noise. The manufacturer sent me a new fan, which I used to replace the old one. The fan runs great, but my graphics card is now spitting out random lines and quickly crashes my PC after startup. When I put the old fan back the same thing happens. I cleaned and replaced the thermal paste on the heat sink under the fan and on the chip while I was replacing it. Is my graphics card fried?