Rockola 471 Princess - My first Jukebox (with missing parts?)

Hi forum, this is my first post and my first exposure to these magnificent pieces of retro engineering.
I was given this slightly tired looking Jukebox recently (gratis) and I'm trying to get it back to working order again before making a decision as to flog it for spare/repair or restore it.





The manufacturer was obviously Rock-Ola and after a bit of research on the internet, thanks to pinballrebel.com, I found out it's a model 471 Princess from 1978.

From an absolute novice inspection of the system I noticed the following faults: 1) It's missing the cosmetic back piece. 2) The tone arm did not appear to be where it should be and hanging very low. 3) An audio wire was disconnected from the stylus. 4) One of the coaster wheels was damaged and replaced with a plastic wheel. 5) A tweeter speaker was missing

So after checking the fuses, a brief, non dismantling, clean and greasing I fired it up (risky I know) and all the lights came on and the mechanics started clicking and whirring. I dropped a few old 10 pences (also kindly provided) into it and made a song selection. Nothing happened! Inside I could see the large wire magazine holding all the records going round and the metal disk the other side of the turntable (the wobble plate?) and the wheel on the front displaying the letters and numbers of the song selection were all rotating and appeared to working.

I then nipped over to jukeboxarcade and got myself a service manual which has helped a lot, although I'm no electrician, I did manage to set the tone arm height (Which had been suspiciously adjusted to the minimum extreme), it has helped me understand the operating cycle and some of the terminology. I think the service manual assumes a certain level of understanding of the reader; an exploded diagram of the machine with all the major component parts and sub systems labeled would have been handy.

How I missed the service scan switch I don't know but it was set to scan. So with the service switch set to operate and a few 45s loaded into the magazine I was rewarded with a level of success. After a few clicks, and a definite flash from within the circuit breaker electric box, the gripper (i think it's called) swung into action and selected a record and placed it on the turntable; at the same time the tone arm swung into position and came to rest at the beginning of the record. Then nothing! No clicks, no whirring or anything!!

Now I didn't expect any sound, knowing the phono wire was snapped, but I did expect the record to spin. I then looked around for any obvious loose wires or to see if I could see anything a miss but couldn't see anything. While doing this I discovered that if I manually moved the tone arm to the end of the record the operating cycle kicked back in, the tone arm moved away from the record and the gripper arm spun into action once more, came across and lifted the disk off the turntable and returned it safely to the magazine. Back to the start of the operating cycle!

I can repeat the full operating cycle if I manually move the tone arm to the end of the record so I'm thinking I found my problem. The motor that spins the record is not working for an unknown reason. But the rest of the cycle appears to be OK.

The service manual doesn't say much about the music cycle itself but after removing the turntable it was pretty obvious which motor is responsible for the turntable movement. I decided to remove the metal plate directly under the removed turntable to get to the motor to have a closer look. This turned out to be not as straight forward as it looked, although it might be, but I didn't have the confidence to start trying to loosen the 20mm (ish) diameter brass(?) center bar. So I put it all back together as I found it.

Upon reassembly, and gaining a little more understanding of the mechanics of how I think the turn table operates I came to the conclusion that even if I get the motor spinning, there appears to be a piece (or parts) of the mechanical operation missing. And this is the reason for me posting today. I'm hoping that someone who knows about these Jukeboxes could take a look at the picture below and confirm that there is (or isn't) something missing. And possibly suggest the part number(s) required to complete the mechanism.



I reckon there should be a wheel or bush with a rubber surround attached to the top of the drive shaft (Red arrow) of the motor placed directly below. I'm assuming this then pushes the remaining wheel onto the side of the turntable and produces the spinning momentum.

I suspect someone has already had a go at fixing this and I'm also unsure of the assembly of the components in the picture below. The bush (red arrow) when I disassembled was placed where the blue arrow is pointing. Now it didn't look right were it was, as the inside diameter of the bush was at least 2mm greater than the outside diameter of the pin it was round. There was also no evidence (scratches) on the base plate of the bush moving around over the years. I also added the washer (green arrow) to keep the spring better in place; although having seen the precision engineering of the overall jukebox this also looks wrong.



Thanks for taking the time to read this post . Any advice will be greatly appreciated as I would like to get the old girl running again, but before I go any further I would like to know if I'm playing with a full deck!

Hi
Verify first that the turntable motor shaft moves, just remove turtable and scan the record basket. The turntable motor operates on 110 v ac. Check that it is plugged in properly underneath the chassis and at the power supply. There is nothing else required at the turntable shaft and idler wheel beside it just check spring is in place at idler wheel. Clean wheel with alcohol no oil and oil the turntable shaft and other moving parts on turntable assembly. The turntable is the type that will also play 33rpm singles along with 45rpm. It may that the turntable shaft is seized slightly and a few turns might kick it back into action. Make sure idler wheel sits snuggly on the inside of the turntable
Clones

Hi Mick,
As you so nicely stated--I agree, the service manuals "assume" a lot ! If you also purchased the parts manual, it should help !
If you purchased these items as a "Service Manual ** PACKAGE**", from one of the suppliers listed above, and did NOT get the parts book and the fold-out schematic for this model --scream at them, and tell us !
I don't think you are missing anything but the mechanism cover --
The item you placed the un-necessary washer on is the speed shifter--it is possible that this is jammed but that washer is not going to help.
What you need to do is select an empty record space, allow the gripper to place itself over the turntable (TT) area (with the TT removed), and observe the motor shaft ( which also needs nothing else attached to it). The shaft itself should now be moving. If not, either the motor is defective, jammed, or not getting power. If i is moving, push the tonearm to the point the gripper motor returns the gripper over the basket and the basket stops. At that point OIL the top bearing, felt wick, on the TT motor with 20 Wt ND oil only. If there is an "oil tube" to the motor bottom, you should do the same. Oil all moving points in that area including the TT shaft. Clean the rubber idler wheel with alcohol, and do the same to the INSIDE of the TT where it contacts the idler. The idler wheel should be held against the motor shaft, and the TT by the spring--Do NOT change that spring in any way !! Re-install the TT being sure to align the idler wheel UNDER, the TT, and it should now turn.
Hope that helps !
Ron Rich

Hey guys thanks for the replies. You've given me loads to figure out! It'll probably be the weekend now (if I'm lucky) before I get chance to look at it again so I'll let you know how I get on.

Hi guys,

Just an update on my progress!

I'm getting to know the machine a bit better now. I've managed to remove the motor, strip it down and I've had it checked out and tested (multimeter) by an (ex) electrical engineer friend Mike at the office and he has given it a clean bill of health; "really surprised if the motor didn't run when powered up".
He also told me to test for power on the jukebox with my multimeter rather than the volt tester I was using as he told me it can give false readings. Having done this I've found there is no power going to the motor.
I must say that I've always struggled with electronics and see it as a bit of a leap of faith; why do the electrons flow in a certain direction?! Is it God's hand!!! Give me hydraulics and mechanical engineering any day; simple cause and effect I can understand!
Anyway, I now know what a squirrel-cage motor is and a little bit about capacitors which is where we think the problem likely lies as capacitors do wear out and this type of motor will not start without a working capacitor. Mike did point out that if the capacitor was faulty then the motor should still run if given a manual helping hand to start; but mine doesn't!
The manual is particularly unhelpful here as at sequence 8 when, the turntable is turned on, it states 'circuit not shown'!
Mike has not seen the jukebox itself and has only looked over the manual for me but having studied the circuit diagram for the power supply he has pointed out that there is a circuit breaker within the circuit and that the a likely effect of a faulty capacitor is tripping the circuit breaker.
So I've found the capacitor, I think, in the back side of the electronics panel where the motor is connected and over the next few weeks I'll be testing it (hopefully it's faulty and I've found my problem!), sourcing a new one and trying to locate the circuit breaker on the jukebox (if it's related)

Hi Mick,
IMHO, that is not a cap driven motor--the .047 you show, is a "spike arrestor"-- That type motor should worked if connected to 117 AC line (mains) voltage, with, or without that .047-- You should be able to read that voltage with your meter--if there, and te motor is NOT operating, you have a bad motor-- Did you take it apart and oil it with the proper oil ?? Ron Rich
(Mick, Please check ,and comply with the PM sent on May 22-to view your PM's click on your name in the upper RH corner of this, or any page)

Thanks Ron I've updated my location. I live in the town of Newport, Wales UK. Famous for being the home town of Desmond Llewelyn, the actor who played 'Q' in the old James Bond films!!

Yes your right. I showed the picture to Mike and he didn't think it was a capacitor either and reminded me that he initially thought it was a three phase motor, that's why he was talking about capacitors; he tells me it's a two phase motor. It's me who's the numpty not Mike!

So I've checked and cleaned the electrics behind the chassis and stripped and oiled the motor with the 20w and the motor is now working again, getting power and spinning as it should!

Thanks for your advice in previous posts. I've removed the spring and washer from the speed shifter. I have cleaned and oiled all moving parts as described and I think I understand how it should work now. However when the turntable is in position it does not spin. I did get a slight bit of rotation when I gave it a helping hand but when I feel the idler wheel underneath it feels loose and not in the snug position it should be. I.e. snug against the driveshaft and the inside of the turntable rim.

Could the spring have been stretched past it's elastic limit? (Someone has definitely tinkered with this before me) There is a circa 0.5mm gap between each winding and it does not appear to have the strength to pull the idler wheel onto the motor's drive shaft effectively. You can see in the picture below that the spring does not put much force on the idler wheel and when under no stress does not pull the idler wheel onto the motor's drive shaft. Or is that normal?



thanks again for your help.

Mick

Hi
On the rockola 461 I have at the moment the spring isn't as stretched and the idler wheel is right up against the turntable shaft. You could try and get an original spring or experiment with other generic springs
clones

Hi Mick, and Clones,
If you want my advise--I strongly suggest that you purchase a new, "exact replacement" spring, from one of the "legitimate suppliers" listed above. The size/tension of that spring is very----no-- extremely, critical ! Too loose, and it "slips". just a bit too tight, and the wheel, and/or the top bearing on the motor is worn out , plus, it won't run at the correct speed ! Also, in case you are not aware of it, the rubber on the idler wheel must be free of contaminants, and soft enough to contact, and grip the inside of the CLEAN turntable. It seems that "people" attempt to change the spring tension, when the rubber or inside of the turntable is at fault ? (BTW--Idler wheel "re-surfacers", are also listed above -- if needed) Ron Rich

Thanks guys. I'm going to source an original spring and an idler wheel re-surfacer and crack on with fixing the other issues in the mean time.

I'm confident now that the old girl will sing again and she's a keeper!

Mick

Mick,
Just try the spring---first--you may not need the idler wheel done ?
Ron Rich

Thanks Ron.

I've ordered this: -

https://www.jukebox-revival.eu/staging/ ... ckola.html

I've not got the part number but this spring is fairly inexpensive so I'll give a whirl and get on with wiring the stylus back up. I've not actually checked that the sound system is working yet!

Mick

I'd like to thank you all for helping bring this old girl back to life. Today, with a new idler wheel spring, a re-wired cartridge and a bit of tone arm adjustment, she burst into life and was pumping out sounds of the 60's once again!!!
The sound quality was a bit ropey at first, but this was down to the condition of vinyl; some of the 45s are over 50 years old and look well worn. When I loaded one of my own, very good condition 45s, into the basket and played it the sound quality improved ten fold. Very loud and very Clear!!
I'm absolutely delighted...
Thanks once again for all your help.

Hi Mick,
Glad you got-it !! Ain't it amazing what the correct part (spring) will do ?? I NEVER understood the mentality of someone who would stretch/shorten a spring--they normally do not change tension, with out human help ?
Ron Rich