I own an 80s #black knight.

My 7 digit display...match and ball number has failed. Only the the far right digit has failed...ball number. It has failed completely...not just a burned out segment. The other digits work completely. I initially figured it must be the display itself however what are odds to have all of the segments on one digit go bad all at the same time.

Where do I start? I have a manual with schematics. I have no spare displays and it looks different than my other 7 digit display boards. Any help would be appreciated, thanks in advance.

Thank you for the info. I will check the schematic and board for test points. I will followup with my findings.

If I had a bad display in the future, can they be repaired? Should they be repaired? I see LED replacements however I would prefer to keep the neon or gas type. All opinions welcome here. Thanks in advance.

The display I have an issue with is the 4 digit display. Coukd I damage anything swapping it out with a 7 digit?