This is what I would do to troubleshoot this:
- Are all the balls present in the through (2) ?
- get the manual if you do not already have it;
- identify if the issue is with the switches/matrix, or solenoids/drive;
- then, pinpoint and fix the issue.
Some guidance below.
Using the self-test button inside the cashdoor, go to switch test, step 18.
Confirm that the two switches in the through properly report individually when balls are present.
Confirm that the outhole switch properly report.
Check that the right flipper (button or flipper EOS) has an extra switch for lane change that is not shorting to the main flipper switch.
If the switch(es) do not report, make sure they are properly gapped, and connector J6 is properly secure onto the MPU.
If still not reporting, unplug connector J6 from the MPU and check if pin 16 into that connector is fine (e.g. not broken or corroded).
Check wiring at switches and make sure there are no broken wires under the playfield.
If the switches still do not report, then there is a good chance that the problem is on the MPU in the switch matrix section.
But, you also will need to make sure there is nothing wrong with the right flipper (button or flipper EOS) extra switch for lane change,
as a short of that switch to the solenoid voltage will blow Z14 TTL chip on the switch matrix section of the MPU and cause that column
of switches (through #1, through #2, outhole and right flipper) to stop working.
Using the self-test button inside the cashdoor, go to step 17.
Confirm if the Ball eject, ball release and hole kicker solenoids properly work.
If they do not, check the fuses F10 & F11 (they might be under the playfield).
Check wiring at coil lugs to make sure there are no broken wires .
Make sure the connectors J3 & J4 are secure in position onto the driver board.
With the machine powered off, make sure that the MPU to Driver harness is properly connected.
If fuse(s) are blown, there might be an issue with the associated drive transistor for the coil, on the driver board.
The machine might need its ground mod too, if not already done.
Good luck !
- Sylvain.