Helping a friend fix up his Shadow and have run into a switch matrix issue that I can't figure out. The first issue was that the switch for battle drop target down was not working. I replaced the switch and diode, but it still did not work. So then I checked some other switches.
I checked most of the other game switches (including locks, left eject, all ramp switches, inlanes and outlanes, and they are all fine. Centre standup (SW 56) originally had no diode, but even after adding one, the problem persisted.
Left rubber seemed to be the first in the problem chain so I checked the diode (after disconnecting it) and it was good. All other diodes seemed ok, but I didn't disconnect them so I'm not sure.
This seems like a diode issue to me but I can't tell where to focus on.
Any help appreciated!