On a soft hit the ball sometimes comes to rest on top of the dropped targets and stays there, and nudging it free risks a tilt.

Ball hangs up on a dropped target bank: targets sit too low, reset spring too long

Cause: When down, the targets sat below the playfield surface instead of flush, leaving a ledge for the ball. On this bank there was no pawl to adjust: the reset spring was too long to give enough tension.

Checks

• Drop the targets and look at whether their tops are flush with the playfield.
• Look for an adjustment (a pawl, a stop plate or set screws) that sets the down height on that bank.

Fix

• Shorten the reset spring a little at a time until the dropped targets sit flush with the playfield.
• Where the bank has an adjustable stop plate or screws for the down position, use those instead.

Systems

• Bally MPU AS-2518-35

Games

• Fathom

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