Phonoland

Hi all found this forum the other day and had to join. My father-in-law bought the JukeBox in the late 70's for a chinese restaurant he bought. It folded, he intern put the jukebox in his vacation house in North Conway NH. Three years ago he sold the house and his wife did not want the jukebox in her house. My wife and I snagged it. Over the past three years I have been keeping her running. Two weeks ago my wife and children were playing records, they smelt burning plastic, ran to the box and shut it off.

This is what it looked like when she broke. As you can see the arm was stuck in the middle. Also the floor board is shot so I have always wanted to replace it, now is time.

After I took out the mechanism out, removed the top and cut the floor out.

Here is the new floor, I was even impressed.

Then I got the mechanism back in, all cables connected and I even pulled all three ballasts and put one in that handles all three bulbs. I replaced a fuse and turned it on and jammed again. I played with the motors, moved the arm to the center and it rejected and stopped.
Now when I select a record the write-in selects it and thats it. All fuses are fine and when I push the select switch from operate to scan it rolls through. I have been looking throught the service manual and trying to figure it out. So basically it makes through step 12 and has an issue with step 13.
Just wondering if its a quick fix. It worked great up until this jam a couple weeks ago.
Thanks for any help.

You will need to find the source of the "burning plastic smell"--
Also--couple of questions--
If you start the scan with the service switch, and quickly return the switch to "operate" position, will the basket "home" ?
If you select two or more pins by hand, will the basket "scan" ?
Ron Rich

Ron Rich wrote:You will need to find the source of the "burning plastic smell"--
Also--couple of questions--
If you start the scan with the service switch, and quickly return the switch to "operate" position, will the basket "home" ?
If you select two or more pins by hand, will the basket "scan" ?
Ron Rich

Can't find anything melted but strange that it was working then i reset it with the arm and now no joy.
I forgot about the return to home on back to "operate" and no it does not.
Nope no scan when I write in by hand.
Checked all the connections and all the fuses. Thought it may be the wobble selinoid.
Thanks for getting back so fast.

Is the wobble plate solenoid-- SWITCH, closing (working well ) ?
Ron Rich

Ron Rich wrote:Is the wobble plate solenoid-- SWITCH, closing (working well ) ?
Ron Rich

Not sure if its working at all. Going through the repair manual not sure if its step 12 or step 13 its getting to. I'll have to read more on it and see what I can see.

Look at the switch--is the actuator "pushed in" ? If so, remove the wires and test the switch, with a good analog meter.
If it's not "pushed in" there is a copper colored, "U" shaped (helper) spring, that tends to snap on those units--is it good ?
Ron Rich

Hi.

My first suggestion is one of the two main mech motors.

You mentioned this a few post back

Now when I select a record the write-in selects it and thats it. All fuses are fine and when I push the select switch from operate to scan it rolls through. I have been looking throught the service manual and trying to figure it out. So basically it makes through step 12 and has an issue with step 13.

Is it still the case that the magazine rolls through when scanning with service switch ?

If yes then one of the motors is at least good.

In which case, I think you should remove the other motor which controls the gripper, and check the brushes for any burning etc.
These motors are notorious for causing problems.

Remove the gripper motor from the mech and plug it into the socket where the magazine motor goes, try a scan and see if the motor rotates.
Do ensure the motor is removed since you will jam things otherwise.

Pete

Ron Rich wrote:Look at the switch--is the actuator "pushed in" ? If so, remove the wires and test the switch, with a good analog meter.
If it's not "pushed in" there is a copper colored, "U" shaped (helper) spring, that tends to snap on those units--is it good ?
Ron Rich

Not sure if it is or isn't hard to see. Disconnected the two wires leading up to the solenoid and switch, nothing happened.

g0pkh wrote:Hi.

My first suggestion is one of the two main mech motors.

You mentioned this a few post back

Now when I select a record the write-in selects it and thats it. All fuses are fine and when I push the select switch from operate to scan it rolls through. I have been looking throught the service manual and trying to figure it out. So basically it makes through step 12 and has an issue with step 13.

Is it still the case that the magazine rolls through when scanning with service switch ?

If yes then one of the motors is at least good.

In which case, I think you should remove the other motor which controls the gripper, and check the brushes for any burning etc.
These motors are notorious for causing problems.

Remove the gripper motor from the mech and plug it into the socket where the magazine motor goes, try a scan and see if the motor rotates.
Do ensure the motor is removed since you will jam things otherwise.

Pete

Yes still scans through when scanning with the service switch. Does not return to home when placed back in operation mode.
I will try the motor tonight.
Thanks.

If the motor runs using the service switch, the motor is not the problem. If it won't return to home, if started via the service switch, it almost has to be the contact(s) on the read-out arm, or wobble plate switch, or service switch. Trace the circuit -- Ron Rich

In tune with this "switch" discussion, I want to add my two cents.
I've worked on jukes, but mainly other vintage electronics, but here's my advice...

On mostly all consumer electronic equipment, the use of "spark arrestor" capacitors are used across switch contacts and relays to quell the sparking caused by make/break of these contacts.
This prolongs the life of the switch, insuring the contacts "stay clean" and free of carbon buildup over time, due to the sparking.
Usually the capacitor is rated for AC service, but 600-1600 volt caps have been used too.
The value is usually in the range of 0.047 mfd, but I've seen other values on occasion.

Wouldn't the implimentation of such capacitors across the many switches/relay contacts be considered a good upgrade, and part of a modern service procedure?
This would only refer to contacts used to send power, such as for motors, lights, solenoids, and such, not for audio or data lines.

Matt,
Most "robotic" switches in all major jukeboxes, since at least post WWII are so equipped.
Ron Rich

Ron, Matt, the use of a cap across switch points is a matter of careful selection. If the cap value is too high it induces a spark when the points close and short-discharge the cap. When I add these I always have to "tune" the right value for the circuit.

Their main value today is quenching noise pulses that can mess up logic circuits.

I have found that in lower voltage circuits a neon glow lamp w/out resistor is better. I fires to dissipate the kickback pulse, but holds no charge and is an open circuit at points short of ignition.

In wallbox circuits I use these across the signal line to kill sparking at the box's pulse generator when it operates a relay in the stepper.

Rob

Ron Rich wrote:Matt,
Most "robotic" switches in all major jukeboxes, since at least post WWII are so equipped.
Ron Rich

Alrighty then!

If the motor runs using the service switch, the motor is not the problem. If it won't return to home, if started via the service switch, it almost has to be the contact(s) on the read-out arm, or wobble plate switch, or service switch. Trace the circuit -- Ron Rich

Totally agree Ron.

There may be a problem with the other (gripper) motor however, its worth checking in my opinion of course.
The reason I mentioned it, is because the first picture shows the machine with the pick up arm stopped in a strange position.

Always good (and reassuring) to be sure that the motors are in good condition first.

If the magazine doesn't return home (with the switch in OPERATE), then there may be problem with the Homing wiper on the rotating wiper board at the end of the mech.
For the magazine to return home, the play relay must be activated.

The homing wiper and wobble plate switch are in parallel and then in series with the play relay.
Once the wobble plate switch is opened (last selection played) then the mag will continue to rotate until the homing wiper goes open, the play relay will
drop out stopping the turntable, and the magazine at the home position.





Pete