Well, I finally managed to get a friend to come over to let me test my PC with his monitor and it worked. As a last chance effort, I plugged the PC back into my original monitor and there no longer appears to be anything wrong with it
. Does anyone happen to have any idea what fixed it? Did plugging the PC into another monitor possibly reset the image? I also pulled the GPU out and put it back in and then blew out the DVI ports with a can of air (which I've done a couple of times beforehand with no luck).
Should I still be worried?