My wife says, “No wonder you are getting great scores, every time the flipper flips, it scores 1,000 points!”.
Hmm, I was too busy racking up points to notice but indeed – just about every time the flipper was pressed, a thousand points was scored and the Roto-Target spun.
Troubleshooting
Troubleshooting a vintage pinball machine starts with knowing what is suppose to happen and figuring out what isn’t working right.
If the game is scoring 1,000 points when it isn’t suppose to – what features score 1,ooo points?
On this 1972 Gottlieb World Series vintage pinball machine that I restored last summer, 1,000 points is scored by getting into one of the three “bases” kick-out holes or hitting the pop bumpers when lit.
Theory – One of these things must have had a switch that was too close and the vibration from the solenoid was causing it to connect.
Narrowing down the problem – I ruled out the pop or jet bumpers because they are not lit on startup and don’t cause the roto-target to spin.
The three bases kick-out holes score 1,000 points and triggers the roto-target to spin so it had to be one of these.
Another hint was the third base kick-out hole was lit on startup. Ahhh, that narrows things down quickly without even reaching for the schematics.
The Fix
Open the coin door, removing the lockdown bar and glass, lift the playfield and shine a light on the third kickout hole. Sure enough, the switch contacts were just about touching, any slight vibration could trigger them.
Pull out the switch adjustment tool and carefully wiggle the switch stack to provide a bit more gap and voila! Easy fix.
I wish they would all be so easy to find and fix!