Troubleshooting the Flipper Opto
The flipper opto works by pressing the cabinet flipper button. That pushes out an “interrupt” that opens up the light beam from the transmitter (LED) in the opto. When the light hits the receiver (photo transistor), the receiver shorts the input to ground.
If the flipper opto is not working, the easiest thing to do is to switch the left and right optos and see if the problem moves with the opto board. If the problem moves with the opto board to the other flipper, then the problem is with the opto board.
The optos age with time. It is possible that the optos have become too weak.
Another issue is that the original flexible black plastic interrupts fail and they do not completely spring back to block the opto. This can lead to the coil overheating which causes the flipper to become weak.
1) If your coil(s) are getting hot while just sitting there, then it maybe possible to fix the issue by replacing the interrupt with a new interrupt or a new opto board.
2) If your flippers are weak, check the coil. If the coil is not getting hot while just sitting there, then it maybe possible to fix the issue by cleaning the optos of accumulated dirt / dust. Try a q-tip with isopropyl alcohol. If that does not fix it, it is likely that the opto is bad. Replace the optos on the board or purchase a new board – see options below.
If Buying a New Board, Which Opto Board to Use?
There are at least three different opto board numbers: A-15894, A-16384-1, A-17316. All three boards are plug compatible so they could be interchangeable but require different positioning in the cabinet.
The A-15894 board / A-15878 was used in the first 7 Bally/Williams Fliptronics 2 games (The Addams Family which is Fliptronics 1, had mechanical flipper switches). This is commonly referred to as the Type 1 Flipper Opto Board.
The A-16384 board has an improved opto interrupter. That fixed the issue where the interrupter would not fully spring back and block the opto beam. This is commonly referred to as a Type 2 Flipper Opto Board.
The A-17316 has the Schmitt Trigger Opto, that has the (5490-14575-00) opto 5 legs, which is more reliable than the opto used in the earlier version. This version is supposed to be compatible with all Bally/Williams Fliptronics 2 games (but we don’t know for certain). The physical shape and screw hole locations may not be the same as the A-15894 opto board, so some physical repositioning may be needed during installation.
If Replacing the Opto on the Board
For those willing to do a little circuit board repair, it is much easier to replace the U-shaped optos. If your board has two optos, replace both of them.
The A-15894 and A-16384 used a 5490-12451-00 opto. A replacement opto that should work is TCST1103 or QVE11233.0086 OPB804. This opto has four wire leads (legs) on it.
The A-17316 has five wire leads (legs) on its opto. This is the Schmitt Trigger opto and the part number is 5490-14575-00 and is available at Pinball Life and Marcospecialties.
The Schmitt Trigger opto cannot be used in the earlier boards and the TCST1103 cannot be used in the A-17316 flipper opto board.