I bought my Gottlieb Roller Coaster last month and started cleaning it up. It played, but was temperamental. It gave extra balls left and right, sometimes ran the scores wrong and in general was wonky. Took the time to clean all the switches and steppers, etc. Got it to the point that it was consistent... With the only recurring issue being it always gave player one 2 ball twos. (First one wouldn't light the ball 2 light, second would.).

It was good enough to enjoy while I started working on the second machine I bought.

Well, long story short... After playing it for the last month, the extra ball 2 issue simply disappeared. It has now played perfectly for 20 games in a row, both one and two player games! Sometimes this old EM stuff just needs to get used to keep it in good shape!