Mid-1950's Rockola Won't Release Cancel Solenoid

[pheff]

Hoping for some guidance here.  I have a 1442 which seems to be working fine except for one big problem - the cancel solenoid won't de-energize until the record ends and returns to the magazine and the magazine starts to move again.  The soleniod isn't stuck - it is definitely energized and will get hot while the record is playing.  Here's a breakdown of the issue:
* from standby mode I can select a record.
* the magazine and carriage will locate the record, energize the cancel solenoid and play the record.  While the record is playing the cancel solenoid on the carriage remains energized and heats up.
* when record ends, the record returns to the magazine, the magazine moves sligthly and the cancel solenoid is then de-energized.
* The machine will then wait for the next selection.

** Is the magazine supposed to move slightly (half a record slot) after returning the record to the magazine?  The manual doesn't say anything about this slight movement at the completion of the cycle.

I have the manual and schematic I am now lost trying to figure this out.

I have checked the following:
* The reversing switch seems to be working correctly
* The start relay appears to be working correctly
* The interlock and interlock release relay both appear to be working; I watch them during the record transfer process and they are locking and unlocking.
* Cancel relay is also working in conjunction with the Interlock relays
* I have been having some issue with the Grap Cam Limit switch but seems to be working, I guess, otherwise I don't think the magazine and carriage would move.  The Grip Cam Limit switch is a bitch to adjust with those cams in the way.

Any suggestions would be greatly appreciate - I love this machine even though it only plays 50 selections.

Thanks,

Paul

[jukenorman]

Hi Paul,
It's the grip cam limit switch which releases the reset solenoids. I have a 1438 manual but I'm fairly sure the 1442 is the same? Sequence 5, selection lever reset and seequence 6, record transfer cycle completed should explain it to you.

Norman.

[pheff]

Thanks Norman. I must have the same manual that you have and it is, mechanically and electrically, mostly the same. Funny that the schematic says 1438=1445, so I guess we are good. I figured that is where the problem must be but I wanted confirmation.

That switch stack is so hard to work on because of it's location. Any suggestions on the best way to work on it? I have removed the 2 screws to move it around but there isn't alot of slack in the wiring harness. UGH!

Thanks,

Paul

[jukenorman]

Hi Paul,
It looks like there may be two things you might need to consider - the switch has two contacts so it may be that the one that resets the reset solenoids might be faulty as opposed to just an adjustment issue.

Norman.

[pheff]

Norman,

Thanks for your help. I was able to get everything working - the spring popped of the Cam Grip Limit switch and some of the contacts weren't quite right.

I have one last issue that maybe you are familiar with. The plunger in the cancel solenoid (mostly for the Odd selections) won't return after being triggered. It just hangs in there causing the same record to play over and over. If I put a meter on that solenoid, I get 24 VDC until the record drops on the turntable then it goes to zero but the plunger will still hang as if being energized - It won't pop back up.

I have taken off the cancel solenoid cleaned it, the plunger and the spring but still has problems. Do you think this means the carriage is out of alignment?

Any suggestions would be appreciated.

Thanks,

Paul

[jukenorman]

Hi Paul,
Simply I don't know! If you turn the power off after the cancel solenoid has operated, does it return? If it doesn't, then it definitely must be some kind of mechanical issue.

Norman.

[pheff]

Yeah, it's a weird mechanical problem. I can remove the solenoid and press the plunger through the carriage as the solenoid would do. It appears that the spring legs of the plunger are getting held up by the lever or something - I can feel the resistance as I pull the plunger back. I'm going to try some other springs to see if the one I have is just to weak to force the plunger back.

Then while working on the plunger issue, I have a problem with the selection circuit. The selection solenoid, for all, records, won't work but I can manually move the lever and it works.

Jukeboxes - it's always something. Definitely a labor of love

[jukenorman]

Selection problems are often caused by either deterioration of the 300uF capacitor in the accumulator or poor contacts on the reset coil switches.

Norman.

[Hildegard]

I stumbled about " Funny that the schematic says 1438=1445 ..."
My schematic says "1438-45". My first Idea was if 1445 is a Hideaway model. But I can't find any such information, and actually model 1440 is the equivalent Hideaway called "Playmaster".
So another idea: With model 1436A Rock-Ola made a model for either 45 or 78 rpm records. Model 1438 which followed slightly later used the first mechanism only for 45 rpm. So I wonder if the addidion "-45" refers to "45 rpm". It's more a guess than knowing. :-)

Difference between 1438 and 1442: First one is for 120 selections, second one for 50 only.

Sorry that this all doesn't help for your problem.

Hildegard

[pheff]

Hi Hildegard,

You are on the right track - the 1442 is the 50 selection box. I can only find the manual for the 1438 Fireball which appears quite similar except for the rotating program mechanism and the 120 selections. I have to do with what I got.

Paul

[pheff]

Hi Norman,

The selection process was working but when I started playing with the carriage it just stopped. The previous owner figured a way to make the Juke free play by bending one of the rachets in the accumulator. I do get the light that says "Make a Selection". Also, if I manually move the selection lever the jukebox runs as normal.
Since All selections are dead I need to find a common issue to the selection coils - perhaps a bad ground or connection. Trying to understand the schematic with the selection coils makes my brain spin.
I think I understand the selection coils but do you know that the Clapper Coils are and what they do? The schematic shows them inside the magazine and for the 120 selection model there are 6 of them. My machine is only 50 selections so I assume there are fewer of them.

Thanks,

PG

[jukenorman]

Hi PG,
I don't have a 1442 manual or schematic but I do have a 1452 manual (but not the large schematic) which I think is Rock-Ola's next 50 selection jukebox so you would imagine they might be of similar operation. The clapper coils are what Seeburg refer to as group relays in their early 50s 100 selection machines. There are three clapper coils in the 1452 - the first one will "group" the first 20 selections, the second the next 20 selections and the third one the final 10 selections. This also ties in with wallbox operation which would be 3 X 20 matrix although the last 10 would be unused for 50 selections. The 120 selection 1438 will be a 6 X 20 matrix. Seeburgs have a 5 X 20 matrix.

The easy way to do free play is to disable the accumulator reset pawl, it's spring loaded. I'm not a huge fan of bending things! When the selection is made, the switches associated with the reset pawl discharge the charge in the 300uF capacitor to make the selection which is why these contacts are usually the problem when all selections are unable to be made.

Norman.

[Hildegard]

Hi Paul,
a 1442 service manual is available at Victory Glass: victoryglass.com/product/part-number-37-1172/
In case you will find the capacitor in the credit unit being faulty, we got reproductions of those made.

Hildegard

[pheff]

Hi Norman,

Here's some mixed news on the 1442. If you recall, I wasn't able to make selections even with the "Make a Selection" light was on. So I was tracing the wires and checking voltages on the wires going to the 5 selector banks and low and behold she started working again. Not happy as I didn't really find a solution meaning it can happen again.

Also, the spring loaded plungers seemed to be sticking and not returning even though the cancel solenoid was not energized. So I looked more closely at the carriage and went through the magazine/carriage alignment. When I went to fine tune the carriage block using the tiny allen set screws - I found one missing. I also remove the carriage block and cleaned it well underneath and found no binding with the plunger. It appears that the binding occurs when the plunger actually comes in contact with the play lever. Of course, when I replaced the carriage block into the mount, I could no longer make selections.

I DeOx'd each of the five banks and the selectors came back to life - Hopefully there was just a dirty connection on the selectors.

The main problem I have now, is that the machine will intermittently play the same selection over and over - only if I shake the carriage lightly will it no longer play the same record - as if that little shake is completing the cancel process. Do you think the tiny allen set screw could be causing the problem by not locking the cancel solenoid in position? If so, do you have any info on the size of the set screw? The parts list just says "ST-2272 Allen Screw" - no size information at all. The screw uses a 1/16 Allen so could it be a #1 set screw?

Thanks for your insight.

Paul

[jukenorman]

Hi Paul,
With regard to the selections, maybe a poor connection on the return line (ground). I would think it would have to be something like that for all the selections not to work?

I'm not sure why you are having the intermittent problem playing the same record, I think I would have to see it. I initially thought the selection pin might not be being fully reset but I think that would be more likely to initiate continuous scanning - although it does seem like it may be pin related. Would you be able to get something like a wooden cocktail stick in there to push the pin to try to prove that? The screw will be a Unified thread. Do you have a digital caliper? If so you can check the dimensions of an existing screw against the table here www.engineeringtoolbox.com/unified-screw-threads-unc-unf-d_1809.html

Norman.