The playfield lamp fuse keeps blowing, and it happens when one particular pop bumper fires. The bumper lamp may flicker when it's hit.

Playfield lamp fuse blows when one pop bumper fires: lamp socket shorting

Cause: The lamp socket inside the pop bumper was shorting when the bumper vibrated: the bulb or socket tabs were touching where they shouldn't.

Checks

• Take the bumper cap off and look at the bulb and socket from the top.
• Under the playfield, check that the socket legs and their wires aren't touching the coil bracket.
• Remember the fault can be in a part next to the one that fires, since vibration can close a near-short.

Fix

• Remove the bulbs, reposition the socket tabs so nothing can touch, and fit new bulbs.

Unplug the game before working under the playfield. Use the fuse rating the game calls for; a member suggested a small circuit breaker in place of the fuse while hunting the short.

Systems

• Electro-mechanical

Games

• Bank Shot

Related tips

• 6 V lamp fuse keeps blowing
• Change pop bumper lamp sockets from wedge to #47 bayonet
• Gottlieb: lamps dim noticeably each time a coil fires
• Wedge sockets in older wide-body pop bumpers: the bulb may not clear the cap
• Repair a loose playfield lamp socket
• Dim or flickering lamp sockets
• Bally lamp sockets are the weakest
• Gottlieb feature lamp burns out after switching to high tap

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