Just helped my friend add a Gottlieb Jet Spin to his collection. Game hadn't been played in 20 years but is VERY clean and fired right up. Game resets and seems to score correctly including bonus countdown, same player shoots, specials, etc.
However, it will not advance past player 1 ball 1. I looked at the other recent posts on this issue and did identify that there was no issue with the trough switch and that the Bx relay energizes and latches (although it was sticking a little at first). Now the problem seems to be that the player unit is just not energizing after the ball drains. I know the coil on the unit works since it resets when you hit the credit button.
When I manually trigger the player unit, it advances correctly to ball 2, ball 3 etc. It will also advance correctly for multi-player games (e.g. player 1, ball 1, player 2, ball 1, etc.).
We have ordered a schematic from PBR (admit my schematic reading skills are only OK) and are waiting for that plus play field rubbers (the current ones were like dry twigs!).
My initial thought was it might be a mis-adjusted switch on the Bx or 'First Ball' relay but I don't want to simply guess at it.
Any help/direction is appreciated.