im having this issue too, started when i put the visor down after typign on my keyboard. immediately lost sight and it was tracking perfectly. based on what ive dug up it seems to be the cable. also i was able to switch the refresh rate several times and get it to work, then when i even slightly moved the visor it immediately went to black. there is no replacement cable as far as ive seen this is probably a situation where youll have to take it apart and fix the cable another way.