Is it possible that the connector is on the wrong pins? Upside down or offset? Maybe the pins got swapped during a connector change? You can also use a DMM to do a continuity check from the switch to the pin on the connector to verify its wired correctly.

I can't speak to the phantom activations, but I know I had to replace several switches in my RFM for some weird behavior and I"ve read that they are commonly faulty.

It's not elegant troubleshooting, but replacing them might be the easy path since it's such a cheap and quick fix.

You'll need to determine if you've got a playfield or board issue. You'll be chasing your tail until you do...

Pinball 2000 Switch Matrix Troubleshooting

The Pinball 2000 switch matrix is very similar to other pinball machine switch matrices, including WPC, with one very major difference. The P2K switch matrix is on the driver board, not the CPU, since the P2K CPU is simply a generic PC motherboard. *This test procedure assumes the switch matrix is not registering properly, with either no switches registering, multiple switches registering, or a row/column short registering.*

The first thing you'll want to do before proceeding too far is be sure that J113, J114, J115, and J116 are all firmly seated into the driver board and the parallel cable from the PC to the driver board is firmly seated at both ends. If these connectors are loose or not properly connected, all kinds of switch weirdness can occur. On some later P2K games, there is an interconnect at the back of the head where the serial and parallel cables could be detached for easier head removal. Be sure to check these connectors too if your game has them.

To properly diagnose a switch matrix issue, you must determine if the issue is a board problem or a wiring/playfield problem. The following tests are most easily performed by removing the playfield from the game so that the switch matrix diagram on the monitor can be viewed while doing the tests.

1-Place the game into Switch Edges test.

2-Remove the connectors J113 through J116 from the bottom left of the driver board.

3-Attach a jumper wire to pin 19 of J116, the connector at the lowest and farthest left of the driver board. Pin 19 is the forth pin from the bottom left of the connector. The connector is numbered as follows...

12 1
13 2
14 3
15 4
16 5
17 6
18 7
19 8
20 9
21 10
22 11

4-Touch the other end of the jumper to pin 1 of J116. If you get the "shooter lane" switch only to show on the test screen as being made when you short those two pins, then continue testing the matrix by shorting the jumper to pin 2, pin 3, pin 4, etc., of J116. Each jumper short should show as one and only one switch in the test.

5-Remove the jumper from pin 19 of J116 and place it on pin 18 of J116. Repeat the test in step 4 for pin 18, pin 17, and so on, through pin 12 of J116. If no, or more than one, switch registers with any of the pin jumpers, then you have a board problem.

If one switch registers for each above jumper short, then you've got a wiring/playfield issue. These can be incredibly time consuming to find, but easy to fix once found. Go over each switch in the game, looking for shorted/broken switch lugs/diodes/wires.

If you can't get the game into diagnostics test with the diagnostic buttons on the coin door, wiring issues are the most likely cause. With the connectors removed as described above, short pin J114 pin 13 to ground to see if you can get the game into test. If you can, then short J114 pin 11 to ground to move the cursor on the diagnostics menu down, and then again short J114 pin 13 to ground, to get the game into switch test. If you're able to get this far without the connectors attached to the driver board, then your diagnostics button problem is not likely the driver board itself, but wiring to the coin door instead.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com