Firepower IC19 RAM replaced

The RAM chip at IC19 has now been replaced, game boots into attract mode now and no longer gets stuck in audit mode. Not entirely sure if it was replacing this RAM that fixed things, or re soldering the 40 pin connector between the boards which is also frequently sited as an issue with these machines.

Game will display credits now when coins are inserted, but for some reason won't start. Pressing the start button seems to do nothing, suspect that the problem rests with the three switches that detect the balls in the trough. Have read that the machine must detect that all three balls are in the trough before starting, and that issues with these switches frequently cause the game to not start.

There is some test mode that will allow you to trouble shoot those switches, so next steps are to read up on how that diagnostic mode works, test the switches, and go from there.