Bally Eight Ball Switch Matrix Problem

[rikshaw]

I think I have a switch matrix problem, but one of the
symptoms is a reboot, so I believe the slam tilt is getting activated
somehow from something on the playfield.

One issue is that the upper left pop would fire a lot randomly. In
fact when I hit the other pop bumper switches, the left pop usually
fires as well. I've also noticed that sometimes when a pop is hit,
the game acts like the ball has drained. Also I sometimes see the
1/9
rollover get activated when a pop fires. I believe the slingshots
are
also causing the symptoms.

What I've noticed is that the outhole, slam, 1/9 rollover and left
bumper are all on the same row.

Also, all 3 pops and the slings are on the same column.

I've ruled out it being an MPU or driver board issue as I have
swapped
them.

I have also replaced the caps on all of the pops and also replaced
the
diodes on the pops.

I have replaced the diodes on the 1/9 rollover and also the outhole
as
well.

I have not replaced the diode on the slam or the slings or the other
2
switches in the same column (right outlane and left kicker return)

Another oddity that I've noticed is that on some of the diodes but not
all, if I put my thumb on one side of the diode and my index finger on
the other side, the switch registers? I've never seen that before.