MM1 Search motor spins continuously - wiper not find hot??

[AlanMacD]

Well, my multimeter doesn't test capacitance beyond 400uF so I cant see if the capacitor is shot or not. I replaced it anyways. No change, still searches. Onto switches?

On a good note, my replacement needle (stylus n77) came for my Shure M77-DA cartridge came so I put it in. Then, I pushed all the pins out from A4 to S6 and loaded it with records and it plays beautifully!!! I can't tell you how happy I am to hear it play... this made my week... I needed something to go right.

[jukenorman]

Hi Alan,
We had to eliminate the capacitor as the problem! In your first post, you said you select V8; have you tried other numbers (particularly, does the "1" work?)? If none of the numbers engage the S1 sprag, then it's maybe likely that the pushbuttons are not the cause and possibly the problem might be the edge connector on the search unit for example? You also need to be aware that a fault on a pushbutton failing to make good contact in the unselected position will cause all higher numbers to not operate.  So maybe you could try a "1" selection.  Now that you know the sound is good, you have real incentive to get to the bottom of this!

Norman.

[AlanMacD]

Norman,
Absolutely we had to check the capacitor, completely agree. I read on some other threads with the continental and other posts elsewhere that that fixed a similar issue. All good. It was fun clipping and soldering, I enjoy this work.

I have tried all button combinations. Then, something good then bad happened!

I pulled the keyboard out about half way to watch the R1 and R5 energize as I made selections. Years ago they bypassed the coin system and when the unit turns on, everything energizes right away. Anyways, I made a selection (cant remember what) and I was testing what voltages I got around the edge connectors. When I got to the left side edge connector (which feeds S2 I believe) all the sudden, S2 engaged and it continued with the selection process, pushed pins out, selected a record, it pulled an empty slot, and then searched a rotation and stopped. Then I pushed some selections, everything seemed to work fine but it wasn't pulling the records I was selecting. for example, if I choose G8 it would pull V3 (using those selections as an example, everything happened so fast I can't remember what was going on). Then all the sudden the after completing a sequence, the R1 and/or R5 weren't energized anymore. I pushed the buttons but they wouldn't latch. So I manually held down the R1 (on the left side) and it would select records, but seemingly random. Then I saw a bit of smoke coming from the search unit area and a I release the R1 and shut everything down. Gave it a few minutes, turned the unit on, and the R1 didn't energize and the pushbuttons wouldn't stay latched.

I am wondering 2 things: 1) Did having the keyboard half way out cause some of the wires to move (as it was leaning against the lightbulb) and that overcame my initial problem of not activating the S2 or 2) By completing the circuit to the ground when I was probing the edge connectors trigger something to overcome the initial problem 3) Maybe if 1 is true, I also moved a wire or damaged a diode for the R1. 4) What the hell was that smoke and did I totally screw this thing up!?

[AlanMacD]

Ok! Turned it back on, gave the short select coil arm a little nudge and the R1 energized. However, when I make selections, it seems random, but at times seems out of phase with wiper arm. Here are the sequences of buttons I pushed (first combo), and what it pulled from (second combo). There were no records in these locations.

V8 - V3 (the wiper arm on the outside selector board landed on the 5 location)
V9 - V9 (wiper arm landed on 0)
V0 - V5 (wiper arm landed on 7)
V1- T6 (wiper arm landed on 7)... then it canceled T6 and went to V6 and then stopped working. R1 was not energized anymore. Giving the select coil arm a nudge renergized it.

B1- B3
C1-C3
 lost energize of R1, nudge the select coil arm but nothing happened.

Very interesting but we are getting somewhere fast!!!!!

[jukenorman]

When the letter sprag relay S2 energises, it opens the circuit to R1 to release the pushbuttons. When S2 then relaxes, R1 should energise provided there is credit, so it would look like you have a dirty contact on the S2 switch that provides the ground to R1.

With regard to the selection issues, the number wiper - is it loose on its shaft?  And that may also be the reason why the sprag wasn't pulling in, if it's loose?


Norman.

[AlanMacD]

Got it! It was out of phase 180 from the selector coil arm. I rotated it, bottomed out the sprag, flipped the wipers and now everything is working!

I can't believe it. I still want to figure out what was the cause, but I think I agree with you that it is some sticky switch in the S2. I'm going to enjoy it for a bit and then take a deeper dive into it.

Thank you so much Norman. It was and is an incredible boost to the confidence to go in there and report back to you for some guidance and follow up with your suggestions. I can't thank you enough! My parents were just here listening to it with huge smiles on their face. The are both from Glasgow, came to the states in 67 when they were in their mid twenties. I told them of all people and places, a man from Aberdeen walked me through repairing this. Isn't the internet great!

[jukenorman]

Great stuff, well done! I did predict that we would get it operating but I must admit that you had me slightly worried when you reported smoke!

Your parents are just slightly older than me (I was eighteen in 1967). There were some great sixties bands from Glasgow although few made it big - the Poets, Beatstalkers, Gaylords (who became Marmalade) among others. I would recommend a bit of period Glasgow music for your jukebox, if you can find it!


Norman.

[AlanMacD]

Hey! Well, it was short lived. Now the buttons won't energize. Typically, when I turn the jukebox on, the pulse latch relay gets energized right away (R1), the latch coil pulled in and pushbuttons stay latched in.

Now, the pulse latch relay won't get energized. If I hold it down, I can make a selection.

Could it be a problem in the re-routing/modification they did so we don't have to add a dime? Like, is it a problem upstream of latch or is a latch switch/contact issue?

[jukenorman]

If you look back a few posts, there was a similar problem after completing a selection and I said that it was likely that it was because of a dirty contact on the letter sprag relay (S2). These potential dirty contacts invariably make a return - so I would start with that. It could also of course be the free play mod. but I would check S2 first. Is the "select" light lit?  There is a "stickie" post dealing with the cleaning of contacts.

Norman.

[AlanMacD]

I read more closely at your second to last post! Yes, you are quite close in age to my parents. I actually have Gerry Raferty's down the line coming in the mail today! I will see if they recognize the other bands you mentioned. My family last name is Piggot, my Uncle Leslie Piggot was a sprinter for UK during a few olympic games.

Yes, I think the contact below the S2 is out of adjustment. I cleaned the contacts and turn on the machine, no change. But if I slight move the right-most contact, I can get the latch coil to load up. How do I adjust it? I saw in the sticky a discussion about bending them, but he didn't use that word. 

I gave it a little encouragement and now the latch coil is staying energized. I notice a big glob of solder on the contact arm that is not staying in contact. It is the second from the right. But now, I am back to square 1 where it wont stop and push a pin, just spinning continously.

So, seems like there is an issue surrounding this S2. What should I do here?

[jukenorman]

The post does cover the adjustment, Ron had said that he uses a small pair of snipe nosed pliers. Adjust the contact blade that isn't actuated, small pliers like Ron suggested, don't adjust in the middle and it usually only requires a minimum of movement, go carefully.

Is the Gerry Rafferty 45 for the jukebox? I used to see Gerry with his very first band before I left school. They made one record which can be found here on Youtube www.youtube.com/watch?v=zPHLs2_rOGE&ab_channel=russallert
I actually have that 45, very rare! Apologies to everyone else for veering slightly off topic.


Norman.