The flipper stays up even with the game switched off.

Flipper stuck up with power off: binding or worn pawl

Cause: The flipper is clamped too tight against its playfield bushing, or (on games with an EOS switch) the worn coating on the pawl catches on the end of the EOS switch, which may be frayed.

Checks

• Check for about 1/32" to 1/16" vertical play on the bat.
• Inspect the pawl and EOS switch tip.

Fix

• Reset the end play with the flipper adjustment tool.
• Rebuild the flipper, replacing a worn pawl and frayed EOS switch.

Systems

• Data East CPU Version 1/2
• Data East CPU Version 3
• Data East/Sega CPU Version 3b

Related tips

• Weak flipper: worn mechanism
• Flipper stuck up with power on (Playboy and later)
• Flipper sometimes sticks up, even with power off: replace the coil sleeve
• Stuck-up flipper: electrical or mechanical?
• Using a Williams pawl assembly on a Data East flipper
• Left flipper stays up until power off: faulty flipper board
• Flipper sometimes stays up until power off: broken coil diode
• Solid state flipper has no power though fuses are good

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)