Working on Bally TZ. Up and Down post (between the flippers) was working fine. Rebuilt all 4 pop bumpers, tightened below play field switch stacks. Bumpers look and work great. When finished with them, up post worked, down post did not.

Checked and cleaned switch contacts, nothing. Checked coil resistance, get a 1, checked nearby slingshot coil resistance get 10.7 to 10.8. Desoldered down post coil wires, no change in ohm reading. Swapped down post coil with nearby slingshot coil with same coil number which was working fine. Then neither the slingshot or down post worked. Coil ohm readings were the same as before the swap. The slingshot coil - now on the down post - showed 10.7. Inspected the former down post coil - found both winding wires broken on back side of coil. Checked ohm reading directly on wires, still 1, clamped wires to lug posts, no change. So know I have to order a new coil for the now not working slingshot.

Desoldered wires from good coil at still not working down post. Used jumpers to connect desoldered sling shot coil wires to the coil at down post, and when hit sling shot switch, coil at down post fires. Disconnected jumpers and checked continuity of green and black wires that connect to downpost coil lugs. Black had continuity at every black, red, and bare silver wire under playfield, including other green wire connection points. Green wire that had been connected to the coil lug had no continuity to any green wire, below playfield, or at Jones plug in bottom left of back box including when I pressed the playfield down post roll over switches.

I have now exhausted my limited troubleshooting skills. Any ideas?

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Unfortunately don't have a schematic for this game. Had it only a couple of months, and hadn't needed it until this fun problem.

Sorry, didn't mention the relay. Answered this, then edited after realizing hadn't tested manually activating the down post relay after swapping coils. Just tested and yes, manually activating the relay fires the coil. Now just have to figure out why the relay isn't activating when the playfield roll overs are pressed.

Also, retested the green wire continuity. There is continuity between the green wire at the coil, and at the down post relay. And at the white black wire from the relay switch stack when the relay is activated manually.

Thank you thank you. Looked at the eos switch at least two or three times before posting the problem. But didn't see that it was just slightly not touching. Adjusted and down post works, YEA. But now a coil is buzzing, the game starts on ball 4, when drains shows ball 5 on the back glass, but goes to game over before kicking out the ball. Will investigate and post back if can't solve this one.

Great, will go get Schematic. But will be marking this one solved. Found buzzing problem, had capped off coil wires for bad coil, but didn't realize coil kept the point scoring switch open. With no coil, was just barely closed. Will be getting that replacement coil pronto. Thanks to all of you for the as usual right on help.