Still having trouble getting this beast up and running.  Here's what I am dealing with now...

The right flipper has 2 switches - one for the flippers and another stacked on top to control the paclite matrix (switch 37).  The second switch is registering as closed during the diagnostics and it does not work at all during game play.

So far I have...
- tested the switch matrix on the MPU
- tested the circuit for continuity between the switch and MPU connector on both wires coming off the switch
- checked all the other switches in the circuit
- tested the diode - replaced it even though it was ok

Not sure where to go next... any thoughts?

Thanks,
newf

Ensure diode is oriented the correct way (it could've been wrong before you replaced it).  The other thing I've seen is the actual switch stack incorrectly assembled and shorting closed all the time.  Check CAREFULLY - EASY TO MISS and make sure you have spacers in between ALL metal blades.

Mike

is there a ceramic capacitor on that switch???? , if yes, cut it !!!! these are getting leaky with times , then the switch matrix pulses go through like a shorted contact !!!!

Bruno

I never ceases to amaze me ho the simplest thing can cause so much grief.  The switch was soldered incorrectly, one wire was connected to the outside switch arm and the other was connected to the metal backing arm of the outside switch arm... I moved the wire from the backing arm to the inside switch arm and bingo... no more closed switches!  I can move freely in the pac matrix!

Thanks MrMikeman for making me go back and inspect that switch a lot closer.

mindstorm88: following the advice @ pinballhq.com I cut the ceramic caps from all the playfield switches for just that reason.

Glad you have found the problem.  I had a same issue in a modern WH2O pinball ones.
By removing those capacitors, the sensitivity of those CPU registered switches goes down a lot.  On some Bally 1980 type games, it really makes a difference to leave them on.  I don't see the point of cutting them out unless you are an operator who has this on location.  I would just replace the capacitors with new one if it is suspected to be bad.  The newer ones (25 years later) are smaller and I am sure leak less over time than those old ones did....

Quoted from 80s.fan

By removing those capacitors, the sensitivity of those CPU registered switches goes down a lot.  On some Bally 1980 type games, it really makes a difference to leave them on.  I don't see the point of cutting them out unless you are an operator who has this on location.  I would just replace the capacitors with new one if it is suspected to be bad.  The newer ones (25 years later) are smaller and I am sure leak less over time than those old ones did....

I completely agree with this statement.
Cutting the old cap is a good temporary solution to check the switch test,
and to play a few games. However new caps (and other spots where original caps
may already have been cut !) should be installed.

These caps were originally installed in these games to extend the switch pulse time
so that all switch closures, even if very short/quick, would be detected by the MPU.

These caps are typically 0.05 uF 50V or 100V disc ceramic caps.... Very affordable.


Cheers,
- Sylvain

Quoted from sylvain

Cutting the old cap is a good temporary solution to check the switch test,
and to play a few games.

Cheers,
- Sylvain

You're totally right !!!!!!!!!!

BSL

Cool, I'll pick up a bunch this week and start replacing them.

Thanks for all the help guys!