Thank you for taking the time to read my post and I appreciate any and all help.

Current Issue: At power on the Mini Playfield does not move and the error log reports the below 2 errors.

- No CW Movement
- No CCW Movement

Although through test mode I the playfield will move up and down smoothly both CW and CCW. however it does produce an Error on some of the movement tests but gives no indication of what the issue may be. The Opti at the bottom is working and has been replaced just to be sure. During Tests, it's status reports correctly on the display. The best I can tell with the tests that fail, it seems that the MPF may not be stopping in the correct spot, but its my understanding that the system, uses the Opti to detect MPF position.

Some history for you. The game was working fine about a month ago. (Minus a few bulbs, and a couple of switches, including the left 2 mushroom buttons/opi on the MPF). While playing it one night a friend reported the right flipper no longer functioned. I later opened up the PIN and found that one of the wires for the flipper had broken. No big deal, so I soldered it back on and went to close the top. Unfortunately I didnt pay close enough attention and some wires from the MPF were hanging down low and caught the speaker and caused some damage. To make matters worse the PIN was powered on at the time. As a result, I have found the following performer the below actions in order. Which has resolved most of my issues.

- Re-soldered the wire to the motor which was pulled off
- Plugged the motor connector back in
- Checked all the fused both visually and w/ continuity test
- Validated the motor wiring back to the bidirectional board
- At this point the MPF would still not move, so to validate the motor and smooth movement I used an external power supply to apply both CW and CCW power to the motor and it moved smoothly in both directions. I had a concern here that I may have left the MPF in a position different then where it started and maybe some how that threw off the game from knowing where to stop, but its my understanding that is what the Opti at the bottom is for, basically so it self adjusts based on actual position of the MPF.
- I was concerned that perhaps the opti was damaged. It appeared to be working correctly, but the IR light was dim (probably just dirty), but to be safe, I replaced the opti board and replaced the opti sensor at the bottom of the MPF. Now the IR is bright and in test mode the opti reports correctly
- Replaced the bidirectional moto board (This got the MPF moving again in test mode) but still give above mentioned errors on power up
- Repeatedly moved the wire clusters around while in test mode to see if any switches or anything activate and none are found.
- While doing the above, i also looked for bad connections or broken wires and found on on a 2 lead connector that had a broken green & white/green wire which I have repaired.

If anyone has any thoughts or suggestions, please let me know. It's almost as if the MPF is just out of sync with what the game is expecting in test mode, but what I find even stranger is that it doesn't even move the MPF at power on and just gives the errors. So maybe there's something that the game checks for on power up that is bypassed in test mode that lets the playfield move.

Thanks

Oh and if anyone knows a good/reasonable Pin repair tech in North GA, please let me know.

Quick update.. While creating the post above, I realized I haven't rechecked the fuses since I replaced the boards. I went back and found that F107 looked in tacked but failed the continuity test this time. I replaced it and now the MPF moves on power on and cycles a few times, but does not finish in the bottom position. Once it stopped in the middle and another at the top. I still get the same CW and CCW no movement errors and the same in the test screen.. the MPF moves, and rotates CW and CCW correctly but still gives an ERROR. It still seems that the system is having a difficult time determining the MPF position although the OPTO is working 100% correctly as reflected in the test screen during the tests.

I created a video on my phone to show you, but the site doesn't allow me to upload it. So if you know a way to link an mp4 or want to see it let me know and I can send it to you directly.

Thank you for your response.

If your referring to the "The Doctor Who Mini-Playfield" yes, I have it. But given the complexity and time involved in pulling the MPF, I have been avoiding that for now.

1st, I want to clarify if it was not clear in my post that the OPTO at the bottom appears to be working properly. When run in test mode I can see the beam break at the appropriate times when the platform moves up and down.

Is there a way I can send you the video from my phone where you can see this as the test runs? Right now the MPF is cycling on power on and before each new ball. It's now stopping about 1/8" too high now. I am not sure what changed from yesterday when it was stopping at the middle position w/ the mushroom buttons at the appropriate level.

I am not familiar with how to perform the below, is there a document or known process you can point me to?

"check continuity from the machine side of the connector back to the CPU board"

I will try to run a full test when I can get back to the machine. but for now the error report only has 3 issues reported. One being the reported for the 2nd opto from the left on the mushroom buttons (the 1st one is also not functioning but isn't failing the test). The other 2 errors are the no CW movement and no CCW movement.

Thanks again for taking the time to reply.

As I mentioned before it was working for years with out issue, so I am confident the gears, etc are all correct and not an issue. The issue only started after that stupid mistake that i described earlier.

I will try to run all of tests 1-14 as mentioned and see if anything jumps out.

As for the video, i have one i made already but the site wont let me attach an MP4 file. Any thoughts how I can upload it for you?

I was able to upload a video to YouTube for you to check out.

Here's the link:

Quick question too.. Do you know what the correct replacement OPTO is for the bottom of the Playfield. Perhaps there is a slight size difference or something in the one i replaced it with.

The one I purchased was from Marco Specialties as mentioned below.

B-79711 - Infrared LED OPTO set Williams/Bally

https://www.marcospecialties.com/pinball-parts/B-79711

Thanks for the post and info.

I looked at the MPU and everything seems fine, but what is odd is is you mention connections on J206 and when I look at mine it seems that J206 and J208 are not used but J207 and J209 are used instead. Even my manual shows it should be using J206 and J208.. Any thoughts on this? Does it matter?

I did see the Green-Orange wire and seem to be solid on both ends, I need to get some longer test leads worked out to test the continuity, but I don't see any issues.

I agree that is sounds like the MPF can't find it's home position, but its my understanding that is what the OPTO is for. I don't see how the green-orange wire to one of the MPF in game switches has to do with the home position sensor.

20220406_151431 (resized).jpg

Interesting, I need to try to understand that better. I thought the optos were all connected to the opto board and then back to the mpu. Do you know exactly where the Green-Orage wire goes/connects to? I have a hard time tracing it past the connector at the bottom of the MPF.

In your case did your OPTO work? Did it report correctly when the beam was detected and broken? I just created a video on mine showing that in test mode, i can see that the beam is detected correctly. If this green-orange wire was broken would that still work?

Is this the link you mentioned for testing? Can you help me narrow down what section your referring to?

https://pinwiki.com/wiki/index.php?title=Bally/Stern

Thank you all again for trying to help.

That last list of steps to take to test GRN-ORG or WHT-RED wiring was very helpful. Be it good or bad news, the 3 tests worked as expected and no unexpected switches triggered.

Here are some screenshots, I also took a video encase anyone wants to see it just showing nothing else triggered.

Any other thoughts?

20220406_171413 (resized).jpg

20220406_171419 (resized).jpg

20220406_171425 (resized).jpg

As for the OPTO board, I just replaced it with a new one. I don't really think the old one was bad, I can try to swap them back for a quick test and see if it makes any difference

Okay, I tried swapping the OPTO board and get the same results with both boards. The OPTO's still appear to work correctly and register in the switch test.

I'm not sure if this rules out the need for the LM339 chips test you mentioned

Thanks again for all the inputs and sorry for the delayed response. The side was limiting my posts until i get verified.

As mentioned earlier, I purchased a replacement OPTO below. But I believe the old one worked just fine and just needs a good cleaning so if needed I can swap them back, but again, I can see it working and in test 14, as the MPF moves, the on screen graphic accurately represents when the beam is broken or not, so I really don't think this is an issue.

As for connecting the motor wires backwards, when this 1st happened only 1 wire was disconnected. However since then I have tried reversing the wires several times and even confirmed that it is rotating CW and CCW as indicated by the test modes, so again, I am fairly confident that this is not the issue. (Basically when it is testing CW if i watch the big medal disk rotate from the front of the machine, it goes CW, and when it tests CCW it goes CCW) I admit at 1st I wasn't sure if it should be viewed from the front of the machine or from the back but found posts saying to view it from the front as i did. if any doubt, i can post videos

As to the comments about the couple mushroom buttons, I know i need to fix these, but they were not working prior to this issue so I was hoping to avoid having to pull the MPF to address that until I resolved this issue if possible.

As for not purchasing from the best vendors, all I can say is that I only have the 1 pin and up till now I haven't had any issues i could not address on my own. This Pin had a few issues like a couple of the mushroom buttons not working from day one but its worked otherwise for like the last 10 years with out an issue.. So, basically I just didn't know any better. I tried the lazy mans diagnostics 1st.. the MPF wasn't working so I replaced the OPTO board and Motor board, and looks like the moto board was bad. so that was one of the issues

Thank you all for your help and I don't want to seem ungrateful, but does anyone have any other suggestions other then pulling the MPF and fixing the 2 mushroom buttons that have been none functional since long before this issue started?

It's just pulling the MPF is going to be a bit bigger project and I don't want to start that till i have time to dedicate to it and knowing the 2 mushroom buttons issue was there before this issue, I don't think that's going to fix this current issue, but if the experts don't have any other suggestions I will have to go down that road when i can make the time.

Thanks for this input. If you can find the images of those connectors you mention and is there any specific process to follow for the repin?

I have not tried moving from J207 to J206, etc. but I can quickly test that and get back to you.

As for the connectors, broken wires, etc. I get it and understand especially for an intermittent issue. Where this is a constant issue (MPF cant find home) I would expect to see some sort of constant failure when testing switches, etc. But everything seems to be working except for 2 mushroom buttons (and as you mentioned I will likely need to order new opto's and housing to avoid light leaks) and the error log just reports no CW and CCW movement but we can clearly see that in test mode it moves just fine, but for some reason it errors, like its not seeing the opto beam break in the right pattern. Thats another reason im hesitant to tear down the MPF until this is fixed, as I dont want to introduce other new issues. As it stands I know the MPF was working for years as it is

I will keep trying to wiggle wires (but so far, in test mode, nothing triggers) and if you can find the above mentioned info on the repinning, ill give that a try too.

Yes, I just moved them and there was no difference.

20220407_104624 (resized).jpg

All the opto board connectors are keyed so they can only plug into the correct location. Additionally if any of the wires were not correct, I would expect to see it when I do the switch test or even in test 14 looking at the MPF diag display. With the exception on the 2 mushroom buttons all switch's and opto's respond correctly.

I can look at reseating all the wires in each of the connectors, but since they are all responding correctly, i again think that's a long shot. Whatever is "broke" is a constant not intermittent. If it sometimes worked and sometime not, it would make sense that it could be a bad connection or something effected by the MPF movement but since its constantly not working, it should logically be easier to find and fix With that said, i can not express how much I appreciate all the input and help with different ideas and troubleshooting processes.

For repin or reseating the wires in the connector what is the best way to do that? is there a special tool needed? I know back in the day working on phone systems, w/ similar connectors, there was a special tool, but in a pinch you could use a flat blade screwdriver.

Okay.. lets take a step back considering what I stated in my last post this should be easier to find since its constantly an issue.

So lets consider this.. As I understand it, and please correctly me if I am wrong.. The only thing that controls the MPF position and HOME is the OPTO at the bottom of the MPF. As mentioned, I had replaced the OPTO board and have tried swapping back to the old (working) board and there was no change so I think we can rule the OPTO board out. I had replaced the OPTO sensor it's self with the below part which looking at he part number from the manual is the kit that contains the correct part # listed sender and receiver. so this should be an exact swap. But given that when the MPF moves we see the sensor beam break as it cycles (as we expect), is it possible that its not getting the pattern its expecting? Is it possible that there is maybe a time factor in how quickly it gets the signals? Maybe the motors running a bit slow or something? It just seems to me that the system isn't recognizing the pattern that the OPTO is sending to it. Does that make any sense? is it possible and how do we fix it? Since it was working previously and I haven't pulled apart the MPF or changed anything that should impact the actual rotation of the part that blocks the OPTO signal, we should be confident that the pattern hasn't changed. The only think that makes sense is it could be running slower or possible but i doubt it, that there is some difference (maybe height or something) from the NEW opto that has changed how or when it detects the break in the beam.. but then again if you think about it logically.. we know the beam is breaking as the wheel turns so its blocking and unblocking the OPTO so the pattern should still be consistent.

B-79711 - Infrared LED OPTO set Williams/Bally

https://www.marcospecialties.com/pinball-parts/B-79711

Thanks.. I have this in my manual as well.. Forgive me but i cant make out all your notes, is there something you would like me to check/test based on this info?

Okay.. so since the OPTO in question is SW#32, thats J5

If I understand your notes correctly, your asking me to check the following?

J5-1 - Not sure what your note here is? "L9"? or A=Grey?
J5-2 - for K=1.0-1.4v? What is LED_RET?
J5-3 - Key position
J5-4 - 12v when blocked,0.1-0.7 unblocked?
J5-5 -Not sure on this one either? E10? E=Green?

Please help confirm what you want me to check here and what I am looking for?

Also, just a quick question. I was pretty careful when i wired in the new OPTO not to wire it backwards from the original, and as I understand it, it doesn't matter. but is it possible to wire that backwards and it would get a blocked signal when it is open and open when blocked? but no that doesn't make sense cause in test 14, you can see the beam line when its open and when its blocked the like disappears, so I have to assume the PIN is reading it correctly.

Thanks for this input.. I will certainly look closer at this and it would make perfect sense. I thought I compared the old and new OPTO to be the exact same size so in theroy it would have the same line of sight.. but who knows

pinballinreno - Just curious to help test, do you know how many times the beam should be broken each rotation.. just thinking i could turn the wheel in test mode and count the number of chimes each time the beam is broken/unbroken in one full rotation.. just a thought

I just compared the old OPTO to the new and they are exactly the same height, but still not ruling out your suggestion. I just need to figure out what size screws and pickup a few longer ones.

pinballinreno - Do you have a link to that thread. I thought i searched and didn't find this same issue, and I just searched again for post and threads by you and don't see it either.

Regardless, I have a call in 15 min.. then I am going to run to the hardware store up the road and get some screws and give this a shot. Hopefully this will be the magic answer.

Thank you all for taking you time to try to help!

At this point the PROBLEM IS FIX!!!!

Thats right.. Thanks to @pinballinreno, I put 4 (2 per screw) small washers under each side to raise the OPTO up and it worked like a charm. Test 14 now competes all tests w/o issue. Also, the boot up error report only shows the one Mushroom OPTO as an issue again.

Quick test of game play and multi-ball and the MPF is functioning flawlessly!!

Thank you again to everyone that contributed. It was a great experience I hope soon not to repeat.

Side note: pinballinreno - I am still having issues finding your original post. That link takes me to the Doctor Who Owners Club, but I don't see anything about the MPF and adding washers to the OPTO. I did a search for posts by you and for anything that mentioner "washer" and didn't find it. Maybe I am just doing something wrong, but would love to see which post your talking about to see if I reviewed it in my original searches and if/why i didn't think that was the answer. The only post i did see was one where you mentioner using washer(s) to tilt the MPF.

Thanks again! you guys have been AWESOME!