Bally Nitro Groundshaker (Bally, 1980) Outhole coil not working right?

[xpaperman]

I have just obtained a Nitro Groundshaker pinball machine (Bally). It had a few issues that I was able to trouble shoot and fix but since I don't really know much about the insides of these machines I need help

When I first start up the machine everything works fine for about to balls. Then the outhole kicker quits kicking the ball out to the plunger. When you lose the ball it recognizes it, gives you your bonus, resets targets and advances to the next ball on the backglass but will not eject the ball. Could this just be a bad coil and need replacing?

 

[Coil_Smoke]

It is unlikely that that the coil would fail in such a repeatable pattern. If the coil starts to function when you restart the game the problem is probably elsewhere. If the coil winding does open when warm check it for continuity or try swapping/connecting a similar(same color) solenoid in your machine to those wires.

 

[pinballdaveh]

most bally intermit. coil problems are bad or cracked solder connections on the solenoid driver board. with machine turned off unplug all plugs on board, remove board, a board removal tool may be needed. reflow all solder connections to the larger pin connectors which are the coil output connections. the smaller pin connectors are the power and data inputs and rarely need any attention. also check solder connections to the row of driver transistors, sometimes if you wiggle a transistor up and down it will show its bad connection, solder if necessary. replace and reconnect board. check for operation in play mode and self test mode. if you still have a problem the card apron needs to be unscrewed and removed to check coil , diode, connections, and operation of the outhole assembly.