Comet: Pinball Repair Log

Comet is one of two non functional pinball machines I picked up for at a Garage Sale about two months ago. The other is Space Station (whose repair log is here).

ISSUES

  1. Battery corrosion — but no leaks.
  2. All displays are dead.
  3. Display Power Supply voltage problem.
  4. All ramps are damaged to some degree. The middle ramp needs repair.

ISSUE DETAILS
Batter corrosion.
[7/13] Removed corroded battery holder and replaced it with an off-board battery holder. Game powered up and played very well (except of course for the lack of displays, and middle ramp issue). Luckily the corrosion does not appear to have spread.

All displays are dead.

  • [7/13] The glass looks scorched. Will have to see if any of the displays work after I repair the voltage problem. I suspect I will end up having to purchase a new set of LED displays.

Display Power Supply voltage problem.

  • [7/17] 100 volts was missing on one of the two 100v pins. When I was feeling around for overheated components, I touched the heat sink of one of the transistors and got a little zap! Since the heat sinks of a transistor should be ground, I believe someone hooked up a replacement transistor without making sure the correct leg went in the correct hole (often replacement transistors legs are in a different order than the original component).

Ramp Damage: Middle / Roller Coaster Ramp

  • [7/15] Side walls at entrance appear to have melted slightly and lean far to the right. This prevents the entry gate/switch from moving out of the way of the ball. With gate removed, a large bump at the entrance still makes entry almost impossible and causes many airballs to fly hard into the glass.
  • [7/16] After talking it over with several people, and doing some reading, we will probably use a heat source to soften the ramp enough to allow us to reposition the warped walls… and perhaps lower the bump. Per the suggestion of both Shane and my father-in-law, we may attempt to use some kid of resin to reattach the cracked lip at the very front of the ramp.

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