Been working on my recently acquired Dirty Harry for a while and have everything working great with one MAJOR exception. The right loop opto (switch 42) is erratic. It is supposed to be closed and then open only when a ball travels through the right loop, then close again. Instead it starts closed, then opens when a ball travels, then might stay open for a while or immediately start switching back and forth between open and close. I checked all the MPU connections when I got the game, so it is not an issue with those connections. All the other optos are working fine, so it is an issue isolated to this opto switch. I understand it is either an issue with the 16 opto board or the receiver and transmitter in the right loop (or the wires that come from the receiver/transmitter for the switch). I also confirmed that the transmitter is sending a light signal and the receiver closes when light is flashed into it.

I can easily get to the 16 opto board and see if that is the problem, but I am thinking that the problem is likely erratic behavior of the transmitter or receiver or misalignment, or something to do with the wires from the transmitter/receiver.

So, my question is: what is the best way to GET TO right loop opto transmitter and receiver? It looks like one needs to remove a good portion of the plastic and steel ramps and some of the mechanisms (e.g., the warehouse including the upkicker wire ramp) in order to be able to get to the receiver and transmitter as they are underneath plastics that are below the various ramps. Please tell me there is some easier way to get to the transmitter/receiver.

Any help would be appreciated. Thanks.

- Brian