Do you by chance have a oscillator or perhaps a spot, middle of the motorboard that looks like somethings missing?
Im going thru trying to isolate a problem with the 0-9 unit that had a bad resistor. it was soldered on the backside of the unit.
It definately goes from the 0-9 unit to the oscillator. This is a game with 3 coin entry which makes a big difference Ive found. Game is King of Diamonds.
good luck!