Quoted from spandol:Thanks enaud, I've reseated the connectors, but maybe I'll try reseating the wires into the connectors. Or maybe that's what you meant.
This is a VERY common Bally/Stern display problem. It is actually caused by one bad display affecting how the other displays show digits. You will need to unplug each display one at a time to determine which one is causing the issue. In other words, the display showing wrong data is not necessarily the faulty display.