The right drop bank no longer resets in a game (it fires in test), another drop target coil is dead, and one bank resets when a different target drops.

Drop target coils misfire after LEDs or a new lamp driver: expander boards need bulbs

Cause: Some coils are run by solenoid expander boards under the playfield that are triggered by an incandescent lamp driven from the lamp driver. An LED in one of those sockets does not draw enough current to trigger the expander.

Checks

• Find the solenoid expander boards under the playfield and the lamps that drive them.
• Check that every bulb in those positions is incandescent, not LED.

Fix

• Put incandescent bulbs back in the expander board sockets; LEDs are fine elsewhere.

Systems

• Bally MPU AS-2518-35

Games

• Eight Ball Deluxe

Related tips

• Drop target falls instead of the ball being kicked out (SEB games)
• Solenoid expander relay buzzes or does not switch
• Expander-driven coils fire in pairs: drop target coil fitted without its second diode
• Expander games: check the controlled-lamp power first
• Expander game ejects or drops targets at the wrong time
• How the solenoid expander board doubles up coils
• Test the coils behind the solenoid expander
• The bulb next to the solenoid expander board must work

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