Problem: On my Indiana Jones, the Path of Adventure mini-playfield "stutters", when it moves in one direction during game play (but not in diagnostic mode). Why?
Answer: The PoA (Path of Adventure) uses the flipper buttons during game play to move left or right. If the flipper opto board's "U" optics are dirty/failing, this can cause the PoA to "stutter", as it moves. Also the game uses two "U" optos on the POA switch board (mounted against the back inside panel of the playfield), and these too could be failing. Use a Q-tip and some Windex, and clean the flipper board optics and the POA switch board optos. Now go to the POA test in the diagnostics. Does the POA stutter in diagnostic mode? If so, the POA switch board optics are failing and need to be replaced. Now retest in diagnostic mode. If the POA works fine in diagnostic mode, but the POA still stutters in game mode, replace the flipper "U" optos (if the POA stutters to the left, it's the left flipper opto board). Another way to test if the flipper optos are the problem is to swap the right and left flipper opto boards, and see if the problem moves to the other side. Note in the diagnostic mode, the coin door buttons are used instead to move the PoA. This is why a flipper opto problem does not show in diagnostic mode, but only in game mode!
