The upper right flipper first fluttered while the lower right flipper was normal; after its coil was resoldered and then replaced, it did nothing at all.

Upper flipper flutters, then dies: pitted EOS contacts

Cause: The EOS contacts on that flipper were badly pitted and not making contact. With the EOS open at rest the coil gets no power, and an intermittent EOS gives the flutter. On this game the upper flipper is switched through a second switch stack on the lower flipper's mechanism.

Checks

• With the flipper at rest, make sure its EOS contacts are closed and clean.
• Check the coil wiring: power to the banded end of the diode, EOS to the fine (hold) winding.
• If the lower flipper works, the shared fuse is probably fine.

Fix

• File the EOS contacts and set them closed at rest; replace the EOS switch when possible.

Systems

• Bally MPU AS-2518-35

Games

• Elektra

Related tips

• Two upper flippers die after cleaning EOS switches: readjust the break-make pairs
• Both right flippers dead, left works: wire at a coil lug not making contact
• Flipper sometimes ignores the first button press: replace the EOS switch
• Flipper won't kick but holds if lifted by hand: dirty or worn EOS switch
• Small upper flipper fires repeatedly and drops: EOS contact tension
• Upper flipper weak and won't hold: second leaf switch on the lower flipper not touching
• Flipper coil diodes must be fitted the right way
• Right flipper dead though coil and switches test fine: cracked joint on a backbox board

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