Only two numbers won't register - CD100

[willymotts]

I have a good CD 100 display, CCC and control panel - all tested in a working machine. When I hook up the panel and display to a machine I am restoring, I can't get numbers 3 or 7 to register. I checked for continuity on the respective wires and it is good. I am at a loss here. Anyone have any ideas? Thanks for your time.

 

[RJ]

Numbers

Take a look at were the board plugs in. Check the pins for cold solder on your keyboard interface board. Any loose wires on the connectors.

RJ

 

[willymotts]

Fixed the cold solder and ran wires directly to check to see if the harness was bad. No change. Replaced the entire upper harness (except for the speaker wires) and it now works. I have never seen anything defy logic like this... Thanks for trying to help.