Get at the trough opto boards for testing

Steps

• Raise the playfield onto its prop bracket.
• Free the left ball-delivery ramp by removing its three nearest screws so it can be pushed aside.
• Remove the four screws holding the third (lower) playfield, unplug its two large Molex plugs (flipper, lamp and switch power) and the two small trough board plugs, and lift it out.
• Unscrew the two opto boards from the trough, lay the third playfield back on its brackets and reconnect the two large plugs.
• Reconnect the opto boards so they hang out the front, then test each emitter and receiver.

Systems

• Bally 6803

Games

• Blackwater 100
• Dungeons & Dragons

Related tips

• Dungeons & Dragons and Blackwater 100 use trough optos
• "Ball missing" with all balls in the trough
• Stop trough optos from breaking with vibration
• Ball missing or balls stacking in the shooter lane
• NTE replacement emitters fit the opposite way round
• Fitting new trough optos on D&D and Blackwater 100

Source: Repairing Bally 6803 Pinball Games from 1985 to 1989, Clay Harrell (pinrepair.com)