A couple of months ago, I picked up my third and oldest pinball machine, Moon Glow made by United. It was in a good state of preservation having been in home use for most or much of its existence. However, it was in need of a lot of attention to get it playing. In its 71 years, I don’t think it saw much maintenance effort. I generally fix my pinball machines so that they are in proper playing order, something more than a shopping but less than a full blown restoration. I like to retain some of the “patina” of these old machines.
I come away from this effort enunciating one word: CLEANING. So many of the issues I noticed when I first diagnosed the machine succumbed to my cleaning efforts. Vacuuming, wiping down surfaces, flushing old grease and debris out of moving parts, cleaning electrical contacts. No tweaking yet, no adjusting yet, just CLEANING. If others have shouted this before, I think it still can use reiteration.
I have arranged the description of my efforts into short sections, not in any rigid order, but hopefully of value to others.
Symptom: Dead lights on playfield. Remedy: Test and replace bulbs.
Symptom: Dark backglass backlight bulbs (supposed to be always on) and tilt bulb. Remedy: Clean and tighten contacts (plugs and sockets) of backbox harness connector.
Symptom: One inactive bumper switch. Remedy: Broken solder connection, repaired.
Symptom: Scoring errors. Remedy: Clean 100,000 point stepper and 10,000 point stepper assemblies including burnishing contacts, cleaning shafts.
Symptom: At start of game, 100,000 stepper reset to 900,000 points, not to all lights out, i.e. zero. Remedy: Calibrated stepper arm positions at game start using red marks after cleaning this stepper assembly. Retightened screws that hold this assembly together as slippage had probably also contributed to the error.
Symptom: Bonus advancing errors, inactive ball drain solenoid (pops up gate that allows balls to reach ball lift at start of game). Remedy: Seemingly unrelated issues, but both corrected by cleaning bonus stepper assembly under playfield in same ways as other steppers.
Symptom: Activating but non-kicking for the two upper kick-out holes. These two run off the same solenoid. Remedy: Replaced loose linkage pivot rivet with an appropriate size lock nut, washers and bolt.
Symptom: Entire bell assembly and lock relay coil were missing. The former, apparently someone didn’t like the sound. The latter, presumably to facilitate free play. Remedy: Left lock coil out. Couldn’t find authentic bell assembly, so installed homemade modern equivalent.
Symptom: Missing one bumper cap. Remedy: Purchased a similar but not identical modern reproduction cap from Pinball Resource. Applied lettering B O N U S using inkjet printed water slide decals. I actually slightly modified a computer font that was a close match.
The very first thing I did was vacuum clean everything except the inside surface of the backglass.
Cleaned flipper linkages.
Cleaned, degreased all solenoid plungers.
Burnished all relay contacts using light strokes with 1500 grit sandpaper.
Cleaned playfield and playfield components. Reglued a few areas where the playfield surface was delaminating. Waxed playfield.
Bumper caps were all slightly warped and would not snap in place securely. I used a pinstripe thin strip of double side adhesive tape around the inside edge of each cap and secured the caps to the bumper bodies.
Sealed inside surface of backglass with several light coats of Krylon triple thick, trying to arrest flaking.
Machine came missing playfield glass and backbox door. Made and painted new back box access panel out of 1/4” inch plywood. Replaced playfield glass with new 3/16” tempered glass.
Front of cabinet wood split to left of coin door. Reglued and reinforced by gluing a new block of wood inside.
A couple of the cabinet inside bottom edge reinforcing corner blocks had detached. Reglued.
Power cord had been replaced by previous owner but original cord was still present from solder joints through staples, wire nutted to new cord. Very brittle insulation on original cord, waiting to crumble and short out or electrocute. Replaced entire cord from solder joints on.
A little touch up of paint on side of backbox where someone has covered over flaky area with a swipe of grey paint. A little touch up of paint above flipper buttons. I mix my own paint colors in small quantities to match.
One of the wooden legs had a split above the bolt holes which I glued.
New rubber rings all around. I swear there were still petrified remains of 71 year old rubber on some posts. Although they should all be white rubber, I used red (Titan silicone) rubber for the flippers (see photo), mostly as a crutch to help remember that the flippers are near the top of the playfield.
Machine came with what appear to be the original pinballs. Rusty, pitted, ugh! Purchased shiny new balls - this machine uses 1 1/8” diameter pinballs.
100,000 point advances can still be sluggish, occasionally not advancing when it should. Maybe a more complete teardown and cleaning of that stepper? I did not disassemble the gear and spring assembly the first time I cleaned.
Balls entering the lower “collect bonus” kick out holes do not always immediately eject. This seems to be by design as a subsequent ball going over a rollover will cause them to eject and tally scores. But when the ball entering one of those holes is the fifth (last) ball, it may just sit there. This machine has no mechanism to “know” when a game is over. If I start a new game, that ball will be ejected as part of the reset, but may score points before draining, which in turn triggers the closing of the gate that brings drained balls to the ball lift for a new game. Result, less than five balls available for next game. Restarting, resetting will take care of this, which is not a big deal for a machine set for free play, but I wonder what happened originally while routing when this extra action would cost an extra nickel. At times, these two kick out holes will activate on their own after a delay, so there might be the facility to take care of this that is currently intermittent.
I made a short game play video, available on Youtube:
The Moon Glow Ladies