Replacement opto receiver dead or weak: try it with the notch the other way

When replacing a trough opto receiver on these games, a new receiver fitted with its notch matching the factory parts may register only when the LED is very close or not at all. Some replacement receivers have the opposite marking, so check the part's datasheet for its pin-out (or try it reversed); fitting it with the notch the other way round made it work. Test receivers with the board out using any working LED transmitter or an incandescent flashlight.

Systems

• WPC-Security (WPC-S)

Related tips

• Mounting a replacement opto receiver
• Replacement opto transmitter and receiver pinouts
• Testing an opto receiver
• Telling an opto transmitter from a receiver
• Opto switches dead all at once
• Fitting a replacement U slot opto the right way round
• Low-sensitivity replacement receivers may not reach far enough
• Opto switches dead or intermittent: check the 12 volt supplies

Source: Pinball Repair help group!! (Facebook group)