Quoted from frenchmarky:
No menu buttons, you just use the test button in conjunction with the credit button.
All those coin door switches and the credit switch are tied to return 7 so since they all are dead you might try reseating the two connectors that come off it, laying under the tilt mech in the cabinet. Return 7 may have a broken connection in the wire bundle where it's attached to the door too, takes a lot of flexing. Check for continuity with meter of return 7 from the connector(s) to any of those switches. Just another thing to check first since you are stuck there. Try reseating A1J5 at the MPU board too for same issue.
Nailed it. Found cut wires buried in the coin door harness. At least one of them leads to the test switch. After some tracing it looks like a prior owner cut the wires from the center coin switch and didn’t connect them back up. Weird! Thanks!!
Edit: yep, after connecting those wires together everything tested ok continuity to the connector. I did get into test mode and it seemed like it tried to start a game. I’ll mess with it more tomorrow and see what the other issues are. Thanks again!