On occasion when I boot up my PC it's a black screen after it posts. I think it might be my GPU. I recently installed and uninstalled the TWIN TURBO II on my GTX550Ti. The G-1 compound was not very adhesive. There is excess still on on the PCB of my GPU. Could this be causing a problem? Is my GPU faulty? I tried testing it with OCCT, but it's not working right now for some reason.