Hi everyone.

Strange switch issues happening on my friend's Road Show which I could use some help diagnosing, please.

Most of the cabinet switches don't work (slam tilt, coin door closed, buy in button, always closed, start button, plumb bob tilt). The flipper buttons and coin door service buttons are all OK. The affected switches are connected in the matrix (13, 14, 21, 22, 23, 24) but I think this might be coincidental. Not sure it is a matrix issue because switches 11, 12, 15, 16, 17, 18 and 25, 26, 27, 28 all work. Switch 24 (always closed) shows as open, but no errors show up on the display relating to this (I would normally expect a 12v error if switch 24 was open but this doesn't happen).

As it is affecting the cabinet switches which are run through the coin door interface board, I swapped this with a working one first. No change. Then I swapped the MPU. No change. So problem is definitely in the cabinet somewhere. While examining the switch wires on column 2 I found that I have continuity from J212-2 (green-red) on the MPU to the non-working switches (i.e. switch 21-24). The only anomaly I detected was someone had run an extra wire from Red's mouth (switch 25, working OK) and spliced it into the green-red wire connecting the coin door interface board to the buy in button (switch 23). I removed the wire to no effect. Suggests to me that someone had tried to reconnect column 2 to Red's mouth switch to fix an issue in the past. But I can't find anything else anomalous in the cabinet. Connectors and wires look intact.

Not sure where else to check from here. Any advice is appreciated.

This helps visualise things a little better. Also forgot to mention that I found the diode on Red's mouth switch to be faulty so I replaced it, but nothing changed.

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Sorry, I just realised I wasn't clear about this in the original post. Continuity from J212-2 to the cabinet switches is good. I did find the crimp terminal in J212-2 was a little loose, so I crimped a new one to be sure. No change.

Connectors look OK. I have verified it is not the board by swapping in a working one.

I have just realised that I should look at the switch row returns that come into J212 as well. The columns checked out OK but I didn't verify continuity from the rows. If all 4 rows are not getting back to J212 (for some weird reason), that could also cause this issue. I might just replace and recrimp this connector to eliminate it as an issue.

Resolved. Damaged crimp terminals in J212. I had assumed since the connector had been redone at some point in the past that the terminals would have been OK. Bad assumption on my part.

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