I recently got a Who dunnit with the reels not working (go figure) but I have got all the motors working and wheels good but the far right reel sensor is not working.

I have:
• made sure it is not the sensor. I moved it to the other reels and works great.

•when the board is unplugged it registers as closed even though the other two reels register as open when unplugged

•followed the lines to the cpu and checked power, everything checks out there

•followed the lines to the board by the front left of the playfield and everything seems to check out there.

•switched the j206/j207 and j208/j209 and the problem is still there

I’m not sure what I am missing or what I have tried that is right trouble shooting. I have been working on pinball machines and fixed some assembly’s, flippers, switches, and soldering but still new to a lot of the troubleshooting so please bear with me with me. Any help is greatly appreciated!

I took photos. Something new happened when I turned the machine on, popped up saying to check fusses and switch, I’m going to post a photo.I havnt checked that yet. I unplugged j206/208 and the error goes away. When i plugged it back in switch 46 that should be open started blinking closed. The switch for the slot is switch 48 but it seems like there’s several things going on. I do have a multimeter!

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Okay. No more fuse issue at the moment. I checked them and everything seems good to go now. I do still have all the other issues though.

I disconnected j5 and all of the switches in test menu read open so that means the issue is on the opto board?

When you say to test “pin 13 of U4” how do I know which pin that is or is it the 13th pin on the 16 wire j5?

I have really never done anything to do with boards so it’s a bit confusing but I will also see if I can read or watch a video on testing something similar to the LM339. Thank you so much again!

Okay I looked it up and you mean these pins? I’m also looking up how to test it with the multimeter.

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Roamin so I was trying to test pin 13 and 14 but I guess I am doing something not correct. I try to test them but I very sporadically get a reading on 13 and nothing from 14.

But while I blocked the enter right hole I noticed the closed square on 48 went away which is great because I do not have the slot opto plugged in.

I then plugged in the opto for 48 and it registers open/closed but only when 47 is open.

Does this still keep it on the 16opto board or move the problem?

So the game says 47 and 48 are both closed (square on the dmd) when I block 47 the square for both of them turns to a dot and says they are open. If I continue to block 47 then plug in the opto on 48 then the 48 responds if I block it or not. The moment I unblock the opto on 47 they both turn to squares and say closed.

To add to this I have realized that I took all of the balls out and switch’s 31-35 are closed. I tried blocking them and they are not responsive but I have not had problems with this before.

I do not have any of that chip but will order some now with sockets and see if that can get something fixed!

The first image is 47. (Solid orange, grey and yellow, black, solid grey)

Second image is 48 (green yellow, grey and yellow, grey and white, black)

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Roamin got some chips and sockets ordered so in a couple days, hopefully we get some positive results!