Quoted from TimMe:

The Zaccaria games were manufactured in Italy, but use components that are very similar to Williams games. So fortunately for us, they aren't really all that different to troubleshoot.
Your description sounds like the drop target reset coils are engaging and staying on, is that correct? If that is what is happening, the first thing I would do is check to see if the score motor is stopping in the middle of a cycle.
There is an index cam on the score motor, it's the cam closest to the motor. You can tell when the motor is at the home position, because the home position is the spot where the cam follower for the index cam has dropped into the detent on the cam.
On the switch stack for the index cam, there is a runout switch that should cause the score motor to always return to the home position. On your game, it's the switch at the top of stack (farthest away from the cam). That switch should be closed and should make the motor run whenever the index cam is not in the home position.
If the motor is stopping anywhere but the home position, the first thing to do is to clean and adjust the runout switch on the index cam.
- TimMe

Quoted from TimMe:

Yes. If the motor has already stopped in the wrong place, unplugging it will have no effect on the state of the machine.
Keep the motor plugged in, and check to see if the score motor index cam always reliably returns to the home position. You need to confirm that is happening before trying to fix anything else.
If the score motor is stopped properly at the home position, and the the drop target reset coils are still on, check the switch on the third cam from the motor. There is only one switch on that cam. That switch, when closed, energizes the drop target reset coils. When the score motor is at the home position, that switch needs to be open. If it isn't, you'll need to adjust it.
- TimMe

Quoted from TimMe:

There's only one switch on that cam, so it should be pretty easy to find.

Quoted from TimMe:

In case you don't know, there is a schematic for your game posted on IPDB (the Internet Pinball Database). You probably want to grab a copy. This schematic has detailed information on all of your score motor switches.
https://www.ipdb.org/files/24/Zaccaria_1977_Aerobatics_Schematic_Diagram_paginated.pdf
The IPDB is a fantastic resource. As always, many thanks to Jay Stafford.
- TimMe

Quoted from TimMe:

Maybe. It depends on what else (if anything) is wrong with the machine.
When you work on an EM with a major problem like this one (the game stalls part way through reset) it's sort of like peeling an onion. Right now you have a very serious issue to deal with because all the drop target reset coils are locking on. That is the highest priority fix, because if you don't address it, you will end up with three fried coils on your drop target assemblies.
Once you fix that urgent problem, if the underlying fault for that is also the root cause of the machine not resetting, then yes the game will be working again. But it could be that there are one or more additional faults that are causing other problems with the machine. If so, you will need to continue troubleshooting and fixing things.
- TimMe

Quoted from KevinD:

Mine has 3 springs. The 2 vertical and the one at 45 degrees.
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