Shortly after a flipper rebuild, the left flipper's fuse blows, and a larger fuse blows too.

Flipper fuse blows after a rebuild: EOS switch barely opens

Cause: The EOS switch hardly opened at the end of the stroke, so the power winding stayed on. Checking it by moving the pawl or crank by hand takes up the slop in the linkage and hides the problem.

Checks

• Check the EOS gap by pushing the coil plunger only, not the bat or the pawl.
• Check the arc capacitor across the EOS for a short, and look for frayed wires at the coil.

Fix

• Re-gap the EOS switch so it opens clearly at the end of the stroke; check all the flippers that were rebuilt.

Systems

• Williams System 11C

Games

• Whirlwind

Related tips

• Every System 11 flipper has an EOS switch and coil diodes
• Weak flippers from pitted EOS switches
• Weak flipper: dirty end-of-stroke switch
• Flipper rebuild kits
• Contact files only on flipper switches
• Flipper rebuild part numbers for System 11
• EOS capacitor for parallel wound flipper coils
• Rollergames upper flipper too weak to make the ramp off the magnet: wrong plunger

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