From your description it sounds like you might have light bleeding into the "A" position. Make a jig that looks like this

bank_opto_jig_(resized).png

In switch test,
Line up the hole with the "K" opto pair, block the beam to toggle the switch, then slide it over to the next pair. Does "A" respond this way?

If you get in the right position you can see the light being emitted by the upper optos reflected in the surface of the playfield clearcoat. Do you see all 4?

Block out the upper optos temporarily with electrical tape. All 4 optos should reflect open. Using an incandescent flashlight, shine it down on the lower optos one at a time. Each one should toggle when light hits the opto.

What are the results of the above?

Hello all,

Instead of creating a thread for this same topic, I thought I would start here. I started helping my father fix a few things on a newly acquired monopoly machine, and we are having issues with the bank door. Presumably, the door will not open because the optos are dysfunctional.

Here's the details: The opto transmitter is on, and the opto receiver functions when tested manually with a light in the switch tests. Despite this, the opto receiver is unable to pick up the light from the transmitter. I believe this partially to be because the clear area in front of the bank door by the playfield is a little foggy and may be diffusing the light. It works with a brighter light, but not those on the transmitter. Similarly, it could be possibly they aren't lining up perfectly yet none are registering.

Does anyone have any tips on how to fix this? I don't imagine I would need to purchase new boards since they are running fine, but I'm curious what others think my next move should be. Any advice is appreciated, I spent far too long on this today haha.

Thank you!

My last post has some things to try.

First off, open the coin door and enter PORTALS menu. Use buttons to start switch test. Use your finger to block the bank optos. Just slowly move your finger over the window inert in the playfield. As you move left to right each opto switch should respond with sound and dot matrix animation.

Do any of the 4 respond?

Hey Cody- I tried this, no responses. Despite this, if I do the same switch test with the opto-receiver removed (but still plugged in) and test it with a light source on the opposite side, it does respond appropriately. It just can't seem to register the transmitter through the clear portion of the playfield. I'm thinking of maybe trying some NOVUS on it to clear up the plastic?

Absolutely. If that window is dark with black dust, it will affect operation.

Update: I got the bank door functional. I didn't want to wait for NOVUS to come in the mail, so I picked up from Meguiar's PlastX from autozone on the way home. I cleaned the inside and outside of the plastic insert in front of the bank. I then used some vinegar windex the rinse it off, and cleaned the transmitter/receiver bulbs. This allowed the light to pass through better. Afterward, I had an alignment issue still so I made a few adjustments on the top and bottom, and now it's good to go overall. All 4 switches are lighting up, only 1 and 3 register in switch test, but most importantly I can play unimpeded so it really doesn't matter. I may try to fine tune later. Thank you all.

When you cleaned the insert, did you remove it from the playfield?