I am in the process of restoring a Bally Star Trek and haven't been able to solve the following display issue. All 5 displays have had some issues. I have 3 of them now working correctly and have the two remaining ones with the center segment out. Both of these had other issues that were resolved and now I am left with these two to deal with.
They have both had there header pins reflowed. On one of them I have replaced the Q19 transistor, the IC decoder chip (with socket) and upgraded the suggested resistors to 100k 1/2 watt. The other one I have also done the resistors and Q19 transistor but not the IC decoder. Both are working correctly except for the center section segment (g on the following chart) across all 6 digits (same on the other display). Also the issue is in the display as if I move them around, the issue stays with the display.
Anyone have an idea what is causing the issue?