The 10,000 reel for every player never advances during a game, although it will reset to zero at game start.

10,000 score reel resets but never scores in play: loose wiper fingers

Cause: On this game the 10,000 reel is driven through the ball count unit. The screw holding its wiper finger assembly had worked loose, so two fingers no longer touched the contact board.

Checks

• Look closely at the stepper units in the circuit (here the ball count unit) and check every wiper finger sits centred on its contacts and touches the board.
• Check the mounting screws on the wiper assembly and contact board.

Fix

• Tighten the wiper assembly, realign the fingers on the contacts, and clean the unit if it is dirty.

EM games have line voltage in the cabinet and live contacts on the units; switch off before adjusting.

Systems

• Electro-mechanical

Games

• Red Baron

Related tips

• 1,000-point reels reset but never score for any player: failed 1,000-point relay coil
• Players 3 and 4 reset but players 1 and 2 never do at game start
• Reset relay stays locked on after scores reset: loose zero-switch arm on a score reel
• Score reels won't all reset and the stepper keeps running: one zero switch
• EM score reel will not reset to zero
• Game keeps resetting after pressing start: a score reel zero switch stays closed
• How the score motor resets the reels
• Score motor runs on and the game never starts

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