1940 Gottlieb Score Card Repairs

1940 Gottlieb Score Card

As previously mentioned. I got this machine in 2013. When I first got it the ball shooter housing was busted. It took me until 2017 to find a good one. Found it at Allentown Pinfest.

Unsightly busted ball shooter housing

Much Better

Back of the cabinet was previously broken off and was replaced by some piece of wood. I had to re-glue part of the back and I added some home made angle brackets for added strength. Otherwise the cabinet would have fallen apart again.

I changed the line cord. Added a 3A line fuse. Redid the 120V wiring to the timer and credit unit. During normal play, pushing in the coin slide would wind up the time clock switch and turn the machine on. After a delay, the clock would wind down, open the switch and the machine would turn off. However, if credits were accumulated during play, machine stays on as long as there are credits on the unit.

The circuit looks like this. This shot is from a Gottlieb Humpty Dumpty Schematic.

I noticed the transformer was replaced at one point. I left it as is. The wiring looked sound.

Under every ball of electrical tape hides a horror

There was a couple of busted male jones plugs (a 10 pin and a 20 pin) I had to change. The thing about these old Gottlieb games is that the connectors used have shorter pins than later games. I managed to find the correct plugs in my pile of parts.

I changed the fuse clips. They were both bad.

Total play meter gave up at 4999 plays

The plastic insulators on the brass armature flaps of the trip banks had disintegrated. Some had turned to goo. Some were brittle and were falling apart. I suspect someone at one point used contact cleaner to clean the trip bank switches. The chemicals attacked the insulators.

Fortunately I found some donor plastic insulators from a parts trip bank I had.

Looking in an early 50's Wico parts catalog, I noticed the insulators were listed so this might not have been an uncommon problem at the time.

Then I tightened up all the switch stack screws. They were all surprisingly loose.

Then I went over and cleaned every switch. They were all caked over with corrosion and old dust. It's easier to do the work with the playfield flipped over.

Then I did the head. Cleaned the switches. Burnished the pads on the contact discs. Small top stepper unit is for the 100 points. Bottom left is credits. Bottom right is is 1000 points stepper. R type relay in the head is for the 100 points step up coil.

One pitfall to avoid on these large Gottlieb stepper units are the insulators on the ratchet gear pins. The ratchet gear has one or two pins for the zero and the open at top. The insulating material on the pin tends to perish and fall apart. The stepper unit frame is either hot or wired to the common, so once the unit resets or maxes out (depending on the case), the uninsulated pin shorts out on the switch blade. So pay close attention to those insulators.

Stepper I had in a box of parts. Easier to photograph

After all those repairs. There comes the time consuming part. Troubleshooting! Troubleshooting is a difficult thing to explain. It's a skill in itself. It involves a lot of observation, circuit tracing and thinking. These old games were frequently modified by the operator, some features were removed. You have to figure out what was done and reverse it. You have to play test the game, try all the features. make sure they work. On Score Card, the Rollover Special feature was disabled. a jumper was removed on the rollover feature stepper.

Special rollover feature stepper.

 Reset arm is actuated by slide.

These old Gottlieb pingames usually had a relay map stapled to the inside of the cabinet. No map in Score Card! So here's what I figured out for relay functions.

Left R relay is the slow drop impulse generator control. Switch stack to the right is the Knock off button.

Right of the Knock off button switch stack is the Hold Relay. On the right is the Tilt relay.

Before the Score motor, there was the Slow drop impulse generator. It generates impulses at a slow and steady rate for the knock off reset and the special rollover features.

Resistor seen in front of the slow drop is for the chime coil. Lowers the voltage. The chime looks like a re-purposed door bell, seen in this machine also, so it seems like it was from factory.

Interesting and random stuff:

Resistor in the backbox is for the TILT light.

Backbox notice.

Time clock. Switches on / off 120V. Pin on slide pushes the arm to wind up the clock

Under playfield, tilt spring. The spring is the same as for the spring bumpers.

A piece of copper was added between the tilt bob and the cabinet armor. It zaps you if you touch the armor. 

Panel Scoring is displayed going up to 69 900 points...

But there's no light behind the 60 000 panel. Maybe that 60k panel was there just for the symmetry of the backglass.

Coin slide and free play coil.

S.P.D.T switch enables knock off button in rest position or energizes free play coil if the slide is slightly pushed in.

Infamous Knock Off button on bottom of cabinet on the left side.

This is as much pinball repair as it's experimental archeology.

Enjoy!