This is a repair archive of a Banjo Pinball. Made by Exhibit in 1948. We usually don't take in games this old. They can be hard to get parts for. This one is. This repair took over 3 weeks to complete. 72 year old games have issues that really are beyond reason. Below are the shop notes:
We have installed the legs. One leg was cracked at the top, it was glued and clamped. One corner leg t-bracket was striped, replaced it. That same corner wood brace was loose, glued and clamped. Installed the legs. Sprayed the whole cabinet with bleach. All 4 legs are missing the t-nuts and levelers in the base, they are ordered, uses stort levelers. 6 internal cabinet braces were off, the glue was destroyed by mold, re-installed. Sprayed the whole cabinet with bleach. A rodent has chewed through a wire bundle near the front bottom right side cabinet. The disconnect plugs were rusted soo bad we had to spray with wire solvent/de-ox and carefully pry the plugs apart, this just to get the playfield out of the cabinet. All this just to get the legs on.
Ordered a schematic. It's just a logical schematic, no cabinet interconnect wiring drawings. This is all we could get. In order to re-wire the cabinet I had to make a schematic drawing to figure out several circuits (Rodents). This took days of experimenting. Replaced the 4 fuse holders, they were ruined. Installed a new power cord with ground to the transformer frame. This game was a 2 wire cord. Jumped many wires in the lower cabinet. The game comes on but is barely running. No lights working, no bells, lots of buzzing. Found the plug connector from the cabinet to the playfield was intermittent on several lines. This was caused by a thick, 72 year old layer, of copper oxide on the pins to the connector. The pins, both male and female, had to be hand filed. They were made of solid copper, not an alloy as usual. During this repair, eventually, all 4 plugs were cleaned with tiny files. Cleaned and adjusted all the relay contacts. The game works better. The lights come on, the coils are stronger. None of the stepper units are working correctly. They are all sticking due to hardened graphite lube. It's everywhere and it's very hard to get off. There is no solvent that works on graphite. It is a very stable compound used in the old days. All 4 stepper units were taken apart and soaked in a super strong surfactant used in commercial cleaning. This made the graphite loose enough to rub it off or spray/brush with water. This was a long messy job. The stuff will not come off your hands or clothing. Re-Greased everything with silicone grease. Cleaned and adjusted all stepper mechs. Fabricated a roller that was missing. Replaced some stripped screws on the reset bank. The timing motor was way out of adjustment, cleaned and lubed. The game plays pretty good now. More to come... Game will be ready soon.
The coin door is missing parts, an actuator and a long spring. Never have seen the actuator before so I made a design of my own. This actuator changes the position of the door switch to allow free play awards. The missing spring is long and must have the correct strength and compressed length. Tried many from our old slot machine parts, found one, works great. Also had to make the bracket to mount the spring. The spring pulls the coin chute back out to home position. While playing the game some of the score lights on the backbox were intermittent. This required removing the "10,000 Step Up Unit" to adjust the backside fiber board. The fingers must be adjusted center on a contact pin. Center it while the stepper is half way through it's full rotation. This averages the position on all the contacts. All the lights in the backbox had rusted light sockets and bulbs. Cleaned the sockets, replaced the bulbs. Clear coated the backglass to prevent further deterioration. The backbox frame pinches the backglass too tight. This was caused by someone swapping the light board from a different machine. That's my guess. Modified the positions of the screws mounting the light board. Testing...
More light socket rust fixed on the playfield. Found some screws to hold the playfield down (were missing). The Dead Bumpers have the wrong caps on top. They are too big, will not stay on. These caps are probably after-market. Same size as that is sold today. The Bumper bodies have a smaller diameter and different actuators underneath. The skirts are very different, just flat circles that press down on a flat metal actuator that protrudes down into a wire spring. The spring can be bent to adjust a circle around the actuator tip. The circle has what looks like a carbide doughnut inside. The skirts are a smaller diameter also. All of this means to replace these parts I would have to rebuild all 8 Bumpers with modern brackets, bases, body skirts and caps. The current parts are working and I rigged the caps to stay in place. We usually replace the plastic parts, not this time. Installed front and backdoor locks. Installed carpet sliders on the legs. Testing...