Hello Bob,
This wallbox is like a chapter of "War & Peace".
Have you checked for dry joints on the selector logic board? If not check this first. Yes the LED displays can go faulty, I have never managed to find replacements with the same pin outs here in the UK, you may be better at getting a new replacement in the USA.
The other alternative is to buy a display off of any jukebox from a R-80s up to R-83 including the RI-2 and CTI-1SC and using the display chips in your wall box.
Regards
Alan
Alan Hood
ami-man
UK