The first thing you can try is to clear the CMOS. (Unplug the PC then switch the jumper nearest the small battery on the Main Board, then switch the jumper back and plug PC back in) If that does not bring video back, then your next step is to install a video card and see if that brings video. If that doesn't work, then try switching out the memory. If that doesn't do it, the last thing is to try another power supply. Just plug into the MB and processor power if necessary. If none of the above works, then your Motherboard or processor is bad. In almost all cases, it would be the MB.