Bally Bow and Arrow (Bally, 1975) (EM) Advice

[MrPed]

I have a Bally Bow and Arrow EM pin. It has started not advancing the ball count consistently (acting like an extra ball was earned). The switch at the drain/ball return appears to be functioning. As I'm a new owner I sure could use a bit of advice.
Thanks

 

[pinballdaveh]

do you have the machine repaired yet

 

[Coil_Smoke]

Ball count unit malfunction?

Check to see if the solenoid on the ball count unit is pulling in when a ball drains. Compare the action to when you work it by hand. Maybe it or the mechanism is sticking and needs a cleaning.