Blocking one opto fires a pop bumper and a flasher, and an unblocked opto causes a row short error that clears when it is blocked.
Strange opto and switch faults: the manual swaps J4 and J6 on the opto board
Cause: The manual's text has the opto board connectors J4 and J6 the wrong way round (the two are keyed differently, so go by the keying and wire colours), and the opto board itself was also faulty.
Checks
- Check J4 and J6 by their keying and wire colours, not by the manual's description, and make sure neither is upside down.
- Check the opto board's capacitor and the 12 V supply and capacitor on the power driver board.
Fix
- Plug J4 and J6 where their keys fit, and replace the faulty opto board.
Systems
Games
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Source: Pinball Repair help group!! (Facebook group)