Bally Twilight Zone (Bally, 1993) Ball Lock Release Weak

[eroomnek]

The upper lock release on my TZ is having difficulty popping the ball out and requires several tries when only one ball is present. If there are two balls locked, then the ball rarely gets popped out and into play. I have replaced the coil on assembly A-16307 assembly and made sure that the end of the plunger was not broken off. Anyone have a similar issue and have a fix for it? Thank you.

 

[pinballdaveh]

lock release issue. since the coil was changed the problem is usually the driver transistor that operates that coil. in that low power solenoid circuit Q46 drives that coil. also a 68 ohm and a 2.7k ohm resistors in that circuit need to be checked. Q46 tip102 might have been stressed and not giving full output. changing Q46 would be the first thing i would try.

 

[eroomnek]

works in diagnostic mode but not during game play

Finally found some time to address this issue again. It is still unresolved, but here is what I have done:

- checked circuit. -60V measured at coil
- replaced coil and plunger
- filled holes w glue and toothpicks retapped to ensure a tighet fit

The ball lock release operates great during diagnostic mode. I can have one ball in the lock hole and two others in the qeueu as a worse case scenario and they are ejected with no issues. However, during game play, the ball lock release is almost non existant and cannot push out one ball on its own.

Looking for direction. Apprecioate your help. Thank you.

 

[pinballdaveh]

is there an opto board or a ball trough with swifches associated with that ball release, since coil is firing correctly during test.

 

[eroomnek]

Yes, there is a ball trough switch to let the logic know that it needs to activate the ball lock release. I just checked the ball trough switch in both diagnostics mode and during game play. It works. Just that during game play, the ball lock release is feable at best. Can't push the ball out of the hole. Still works in diagnostics mode though.

 

[pinballdaveh]

do you get a strong coil fire when you ground the tab of Q46 driver transistor during play mode and during attract mode? if you do get a strong fire on both the problem is prob input related such as cpu , data lines , or connections.