I am currently trying to resolve a WOZ ECLE problem and could use the assistance of the great Techs here on Pinside:

Problem: As soon as I turn the machine on, the upkicker to the castle playfield and ball lock bar solenoids fire continuously (munckinland playfiled)

What I have done:
1) Checked the switch matrix, shows both optos as expected for the solenoids to fire.
2) I have confirmed that the Optos, Cables and Opto boards good on both components

I figured the issue would have been somewhere along the opto chain but that is clearly not the case.

What else should I be checking?

Thanks,
Dave

Yes the switches do register when I pass a pencil through the beam. I also confirmed the optos work by patching them to a different port on the Opto board and even swapped in one of my spare opto board and got the same results.

Yes the opto cables have been confirmed to be seated in the opto board.

Hi Lloyd,

Seems I responded incorrectly to your question earlier. It turns out that if I pass something through, neither opto registers in the switch matrix test screen. Does that point to bad optos?

Thanks,
Dave

Unfortunately, using the unused port on either opto board did not work.

It seems that my troubleshooting has confirmed the problem is not the Optos, or cables to the optos or the opto boards. Therefore I guess all that is left is the connection from the MPU to each opto board. Interestingly, the problem is on the same port of both opto boards under the playfield.

Troubleshooting:
1) Plugged connector of failing opto to unused port of opto board and while it registers when plugged in, it does not resolve the problem
2) Plugging in the connector of a working opto into the port of the failing one does not register anything at all on the switch matrix
3) Plugging in a spare known good opto on the failing port does not register. (it does on a working port)
4) Swapping a new Opto board on either side results in the same exact conditions
5) Each switch in the same row have been tested as expected

Any ideas of where to go from here?

Thanks,
Dave