Rock-Ola 464 Write-In Issues

Hello everyone Great forum you have here.

I'm having a bit of trouble with the AC write-in motor on my Rockola 464. I've tested the wiring harness and it's putting out 25.5 VAC steadily once a selection is made. The carriage itself seems to move freely. However, even after disassembling the motor, de-greasing, and re-greasing the gearbox, the problem still remains. It almost seems like the rotor is binding up but the brass gear doesn't appear to be stripped, none of the gears inside were stripped. In fact, the binding doesn't occur until the rotor is added to the mix. I've oiled with 20wt ND oil and still no go. I might have a juke that I can grab the motor from, but I would've liked to keep that as a spare.

Only thing I haven't really tried yet is running the motor without being bolted to the chassis.

Just wondering if anyone has any suggestions?

Thanks!

You have hit on what I have had problems with in the past--so much so, that I NEVER dis-assemble that motor now--just clean them, while assembled !
It is strictly an "alignment" issue--I have removed them and set them on a bench, and applied power with the two screws loose--and tightened them slowly--This works sometimes--others not-- Please let me know if you discover a better way ! Good luck !
BTW--Is there a motor manufacture's name, and a "spec number" on those? Ron Rich

Hi Ron Rich,

Thanks for the tip! Is it normal for these motors to become mis-aligned over the years? Before I even touched that motor, it was exhibiting similar 'alignment' issues which is why I ask. I am glad that it has some fresh lubrication in there though. I wish I had a power supply for this task; do you have any tricks for powering the motor while it's out of the cabinet?

Next obstacle is the amp...There is a mfr name on the unit, I'll get that for you when I look at this thing again, hopefully tonight.

EDIT: I got this thing running. It seems like alignment was only half of the issue. The other half is kind of embarrassing . When I spun the write-in carriage by hand it seemed to glide pretty easily... apparently not easily enough for the motor to handle. I didn't see any grease on the write-in side that could be freshened up, so I put a light film of lithium grease on the path of the write-in carriage for giggles, and sure enough it seems to run great! BTW, the motor seems to be a "Motoresearch" if I read it correctly.

Thanks for all the help,
Hope this can help someone in the future as well.

Darrell

Hi Darrel,
If it is a Motosearch, and has the "spec number" stamped on it, I THINK that the company will rebuild it to specs, for a very nominal fee--
I had a very old one about 15 or so years ago with a stripped gear, and contacted them,--no problem--looked and worked like new--for either 25, or 35 bucks---
BTW--without the number on it, they will not touch it --
Ron Rich

Wow, that is good to know! If the motor is ever damaged through normal wear in the future there is still a way to get it serviced.

I lied, my immediate next step on this juke is the power supply, I noticed the other night that the power cord has a nice slice in it, ground pin removed on plug, and it looks like the original cord anyway. Since I'll be in the supply anyway, is it worth it to replace the selenium rectifier with a diode bridge? If so, is a resistor necessary?

Thanks!
Darrell

Hi Darrell,
It's my opinion that those rectifiers need not be replaced, as long as they are still outputting the correct voltage. Others tend to dis-agree---
As for the resistor--depends on the output of the new one-- IMHO, a fuse MUST be added, on the AC side, if changing to a bridge type.
Ron Rich

When I took mine apart it looked like this:

The small brass gear was mostly stripped. I didn't have any problems realigning when I put it back together though.. At first it actually moved the write-in arm but of course got to the stripped part of that brass gear and bound up. But if I can potentially get a new gear or have it rebuilt that would be fantastic.

I tell you though Derail, Ron is the man when it comes to this stuff. And jukeboxparts and needles4jukeboxes are the best places for parts/etc.

Curtis

Curtis, that's about what my motor looked like. I was able to get all of the old grease out and renew it. I think the problem with the motor is that I had the two screws that secure the stator(?), torqued down too much. Loosening these and greasing the write in track solved the issues.

In reference to the silicon bridge question, I looked at the schematic for the power supply and I'm only seeing the symbol for a diode bridge, I can't see from the schematic that there's a selenium in there. Is it possible that the 464 supply used a silicon diode bridge to begin with?

Also, while I was working last night on the juke, I had originally thought that it just had a weak sound from years of use, and figured a re-cap would take care of it, but when I listened further, the whole left channel is dead. I haven't checked inside the amp yet, but I'll check for loose connections and dirty contacts to start with.

I tell you though Derail, Ron is the man when it comes to this stuff. And jukeboxparts and needles4jukeboxes are the best places for parts/etc.

Agreed

Thanks for all the help!
Darrell

How easy would you say it should be to spin a "healthy" write-in motor/gearbox?

I have one on the bench right now and am debating opening it up and cleaning it out. Judging by the rest of the unit, I'm sure it looks like the pics above if not worse.

With the unit mounted I can spin the write-in arm fairly easily, but there is a bit of resistance coming from the gearbox. I'm not sure if its good or bad resistance though. It feels like I'm trying to get a flywheel moving (can really hear the gears spinning too).

With the unit off, turning the main gear is fairly difficult. More so then I would expect. Should it be easy?

Just trying to decide what to do while its all out anyway.

Thanks.

From my experience it should be fairly easy to move. I would imagine that the motor is really putting forth some effort if you can't move it while the machine is off. But before you take apart the gear box try and see if you can lube it up a little being careful not to get it on the actuall brushless motor. This might work and save you a lot of time and effort. Also, you don't want to strip the brass gear so be very careful and cautious forcing movement.

But Ron is the expert and will be able to better advise.

Curtis

Hi Guy's,
If they move, I do not "mess with" them--as was written--I have had problems with those two screws--too loose and it will work it's way apart-to tight, and they "bind"--that's what I was referring to earlier when I said "alignment"--
Ron

Small Update: Had the supply apart fitting a new power cord, and noticed that Hot and Neutral leads have a spade connector crimped on. These are in turn connected to a silicon bridge, no selenium to be found... so it looks like it'll be left alone until there's a problem.

Still haven't looked at the amp, but I'm hoping that it's just dirty contacts on the driver board for the left channel; we shall see. Just a question on re-capping though, does every cap need to be replaced, or is it only ones within a certain range of capacitance? The ceramic ones should be ok, right?

Thanks
-Darrell

Darrell,
If you are still "talking" about the write-in motor, it is AC, not DC--
I usually change all "paper" and "lytic" types--ceramics if not chipped, or otherwise "broken", are usually OK--Unless they are "Solar" brand--then I change them ! Ron Rich

Hi Ron Rich,

Sorry if I didn't clarify, I replaced the wall cord running into the actual jukebox power supply. I was just making a note for anyone in the future curious, that there's no selenium rectifier to be replaced in my 464's power unit, it's already a sil rectifier.

Thanks for the tips on capacitors! Will post back results

Thanks,
Darrell