HP-97 decimal point with ghost segment d

[AndiGer]

Thank you for the valuable advice.

Cleaning the boards with IPA - especially the connectors and the holes didn't change anything. No real gunk found on the board.

What I just saw today: The battery low indicator LED is a little bit on although the battery is fully loaded (you can see on both images if you look carefully). With the same battery the power low LED isn't seen on the other fully working machine. Maybe by accident maybe both effects deal with each other.

@Tony: What would you suggest to examin with the oscilloscope? I can do that as I have one handy.