A slingshot, kicking target or other rubber kicker stays energised, smokes or melts, and its switch contacts are burnt or pitted.
Slingshot or kicking-target coil locks on and burns
Cause: These kickers are not run by the CPU: their playfield switch closes the coil circuit directly, with no fuse and no arc suppression. A mis-gapped switch that stays closed holds the coil on until it burns.
Checks
- Look for blackened or pitted contacts on the kicker switch.
- Check the switch gap so it opens fully once the rubber relaxes.
- See whether the coil already has an inline fuse on its power lead.
Fix
- Regap or replace the switch and replace a burnt coil.
- Fit a 3.3 uF 100 V capacitor across the coil, positive lead on the lug that has the banded end of the diode.
- Add an inline 3 A slow-blow fuse on the coil's power (non-ground) lead.
Systems
Related tips
- Haunted House has six switch-fired kickers that need fuses
- Coil stuck on that is driven through a playfield-mounted power transistor
- Coils lock on from a bad playfield ground plug pin
- Pop bumper locks on as soon as a game starts
- Coils pulse briefly at switch-on on Volcano, Black Hole and Haunted House
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part Two, Clay Harrell (pinrepair.com)