Advice for repair/ideas, Rock-Ola 442, making some progress

[Ron Rich]

Hi Ollie,
I also suspect the same thing-- Are there any "small motor repair shops" there ? If yes, you might try for a repair n that motor ?-- Ron Rich

[Ron Rich]

Hi Ollie,
I also suspect the same thing-- Are there any "small motor repair shops" there ? If yes, you might try for a repair on that motor ?-- Ron Rich

[jukenorman]

Hi Ollie,
When you measure 3 ohms between + & -, that will be a single winding you are measuring. You could crank the motor round to the next winding etc and check it. But in reality it would be more straightforward to do these checks across the commutator with the armature assembly removed. And then, it's probably only going to confirm what you already suspect!
Norman.

[ollie]

Thanks guys, I have contacted a motor repair shop, the rate for a re-wind is in the usd 150 range.
I´m not the person paying for it, (owner of the Juke is..he is ok with it) so, I´m going to send it out and hopefully
it will get repaired..I´ll let you know later on,
Cheers, Ollie

[ollie]

Hi all, I just want to update you guys on the latest developments.
Today I hooked up a good motor on the magazine for this 442. (one that I had tested and it spun good on my bench at .3 - 0.5 Amps)

Same thing..the "Scan function" does not work.. still, I have no -33V DC at going to the Magazine motor.
All fuses ok, tested new diode on the Play Relay, same thing, have the stock there now back again (tested diodes various)

Like mentioned before for the Scan function:
When I press/hold the service-lever to Scan,play relay moves in/clicks, The Platter spins, but nothing else happens..
My problem is this,
Somebody has tinkered with the play relay before me, and there is an extra diode on one of the black wires
which seems to be cut.. and I do not know why, or why they put it there, or where it went before they cut it?

Now, I do not know what this relay looks like when untouched, so my question is:
Does anybody have the possibility to take a phote of their Play Relay and Email me?
one where I can see the wires/cables going to/from it?
[e-mail]

That´s all for now,
I will upload an image of my relay..

Many Thanks, Ollie

[ollie]

ibb.co/PT6pnx6
ibb.co/p2JzRC8

Images of Play Relay

[jukenorman]

Hi Ollie,
Does your manual have a parts list? If so, page 40 shows a couple of diodes associated with the play control relay. I only have a pdf of the 442 schematics and the quality isn't very good but there does appear to be a diode between the fuse (-30V supply) and the NO contact (page 30 schematic also refers). There is also a diode shown across the coil of the play control relay (to disipate back emf) in the parts list which seems to be shown as a resistor on the schematic. You should be easily able to identify that changeover contact set on the play control relay, the NC contact should have a 2.4 ohm 3 watt resistor attached. I hope that helps?

Norman.

[ollie]

Thanks alot Norman, the only schematics I could find/buy and download was the "444" version. that´s what Im looking at here.it´s pretty similar
in terms of play relay I would assume..but I know it´s a different machine in many other ways..sure..


The play control relay looks pretty similar schematics wise as my 442.
The stock diode goes between purple/yellow wire -33V DC in and yellow/green wire, Across the Relay. see link to scan of my schematics.

ibb.co/KKcSTbk

I assume the "coil" in the schematics for the relay is the actual Coil in the relay, the one that pushes the contacts together? no?

And, I assume, that there should be -33v dc out the green/yellow wire when I press the "Scan" lever? or ?
The record platter/disc spins ok as I hold the Scan lever up.
The 2.0 ohm resitor is there ok.


Stock Diode is called: P100J gi745 play control relay diode #23 part listed as 44875.

I tried a new 1N4003 there instead, but to same effect. so, put the stock back in. acording to my multimeter diode tester, the stock one seems ok.
The 1N4003 is rated at 1A, motor takes 0.5A, so I guess it should hold up?

I found this:
alt.collecting.juke-boxes.narkive.com/aYz18Oz6/rockola-442-tech-help

This is getting frustrating for me as a hobby repair guy (haha!) since I do not know what worked or didnt before I started troubleshooting, or
if there has been functions bypassed/modded, or why..?
I normally work on amplifiers and HiFi equipment, usually succeed, but this relay managed machine is a bit beyond my skill set.

I know the DC motor works, (on my bench 30V DC, 0.5 A) but I see no dc either to the motor cam switches or motor or before it.. I see -33V DC on the purple yellow wire leaving the 1.6 A fuse, but where it is suppose to "leave" the Play Control Relay I have no idea, confused.. haha!

Thanks for your patience and help!

Take care, Ollie

[jukenorman]

Ollie,

There's a diode in the 442 that's not on the schematic that you have posted. I will study your reply above a bit more closely later. I will send you a private message meantime.

Now that I have sent you a copy of the parts list, you will see the additional diode in the 442, that's not in the 444 schematic that you posted above.  This is the diode that's referred to in the alt.collecting.jukeboxes link that you posted.  If that diode is missing or defective, there will be no -30V DC for the motor.

Norman.

[ollie]

i really appreciate it

[ollie]

Hello Norman and all, Studying the "proper" 442 schematics I think I´m onto something.
The diode in question is reversed in for my Realy! see link:

ibb.co/PT6pnx6

(still active as of 7pm UK time, might be erased soon?)

You can see if you Zoom in/expand that the diode (soldered in) is in the wrong direction, hmm. Haha!
Next time I´m tinkering with it, I´ll reverse it so it flows in the same direction as in schematics..
Hopefully, this will fix the problem..(I have spare 1N4007 Diodes to use..(in case the one in there now is shot)
Many Thanks!
Cheers, Ollie

[jukenorman]

Yes Ollie, that diode does look like it's the wrong way round!
Norman.

[Ron Rich]

Page is gone-- 2:10 PM Pacific time USA-- Ron Rich

[Ron Rich]

Check that diode-- I have seen a few miss-marked diodes ! Ron Rich

[ollie]

Uploaded again for you Ron! should be there for 24h.

ibb.co/ThmpTws

Cheers, Ollie