The left flipper kicks up, sometimes with a double tap, but drops back down instead of staying up while the button is held. The end-of-stroke switch looks fine.

Flipper fires and double-taps but won't stay up when held: bad flipper coil

Cause: A fault in the flipper coil itself: the power side fires but the hold side of the coil was not working properly.

Checks

• Check the solder joints on all three coil lugs.
• With the game on and the coin door shut, measure DC voltage from each of the three coil lugs to ground; all three should read the same. A lug that reads low or unsteady points at the coil.
• With power off, measure the two windings against the coil chart: the power winding is only a few ohms, the hold winding is far higher, and neither should read open.

Fix

• Replace the flipper coil (photograph the wiring first so the wires go back on the same lugs).

Coil lugs carry high DC voltage when the game is on; measure carefully and keep the coin door interlock in mind.

Systems

• WPC-95

Games

• Attack from Mars

Related tips

• Flipper fires then falls straight back
• Flipper works on and off or drops while held
• Fliptronics flipper does not work: test the flipper opto board
• Fliptronics: flipper will not hold up (flutters)
• Fliptronic flipper dead though the button reads
• Fliptronics: flipper coil gets hot after a while of play
• Checking flipper buttons and EOS switches in switch test
• End-of-stroke switches: pre-Fliptronics versus Fliptronics

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