While trying to replace an old graphics card with a new one from Nvidia I followed the instructions here and blacklisted Nouveau since only the old card was being recognized via that. Unfortunately now I can no longer boot at all since it seems no card is recognized at all anymore. The motherboard just beeps 5 times about a minute after powering up and all I see is a black screen.
What are my options now? I can't figure out how to access the machine at all at this point.