Everything else works, but at the start of a game the ball is never kicked out of the outhole. Pushing the outhole relay in by hand makes it eject.

Ball never ejected from the outhole at game start: dirty score motor switch

Cause: The score motor switch that fires the outhole kicker (marked C7 on this game's schematic) was dirty and not making contact. Cleaning the outhole switches alone did not help.

Checks

• Use the schematic to follow the outhole kicker circuit; on this game it runs through a switch on the score motor, and a score motor run switch on the bonus collect relay is also involved.
• Watch the score motor switch stacks while starting a game and check each contact in that path closes.

Fix

• Clean (and adjust if needed) the score motor switch stack in the outhole kicker circuit.

EM games have line-voltage circuits: unplug the game before working on the score motor switches.

Systems

• Electro-mechanical

Games

• Riviera

Related tips

• Ball not kicked out of the outhole at game start: score motor 1D switch
• Ball only rolls halfway up the shooter lane from the outhole
• Start-up sequence keeps firing the outhole kicker: outhole switch barely closed
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• Manual ball-load games: ball release switch blocks a new game
• Gottlieb resets but won't serve the ball: bonus unit not at zero

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