Some drop targets in the bank don't come all the way back up when the bank resets.

Drop targets don't all reset fully: rebuild the reset and face the worn reset bar

Cause: Wear in the reset mechanism: notches worn into the reset bar where each target's arm has rubbed for decades, plus worn shoulder studs, e-clips, target springs and a coil plunger link whose hole had worn egg-shaped.

Checks

• Take the reset bar out and look for notches worn where the target arms push against it.
• Check the plunger link's hole, the shoulder studs and e-clips, and each target spring for wear.

Fix

• Rebuild the reset mechanism with new shoulder studs on both sides, new e-clips, new target springs and a new coil plunger link.
• If no new reset bar can be found, cut a hacksaw blade to length and fix it along the worn face of the bar (self-tapping screws through the existing holes worked here; trim any screw tips that stick out) so the arms push on an even surface.

Unplug the game before working under the playfield: EM games have line-voltage circuits.

Systems

• Electro-mechanical

Games

• Old Chicago

Related tips

• Large Gottlieb drop target bank won't reset: worn or sheared pivot rod
• Gottlieb EMs with large drop target banks
• Setting drop target reset coils to prevent metal fatigue
• Vari-target doesn't fully reset and the score motor keeps running
• Drop targets will not reset or stay up
• Realigning a roto-target

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