Rockola 440 (disabling coin operation)

[kestrels]

Hello all,

I received the Rockola 440 manual a couple of days ago and find it just as fascinating as the inside of the jukebox. I understand how important it will be. I see that chronological analysis is the best way forward. With that in mind I would first like to figure out how the coin operation was disabled and how credits are accessed on this particular Rockola 440. I also want to be certain it wasn't some kind of temporary "rigging" as well. I would really appreciate any input on that. Perhaps, someone might know what common methods were used to disable 440s or similar jukeboxes and how to tell what method was used here.

Briefly about this Rockola 440's current operation:
After making a selection, the write in arm spins around and stops at the selected pin. At that point the current limiting lamp flashes, you clearly hear a relay (or relays) click and no other movement occurs however I've noticed a persistent hum coming from the keyboard solenoid after that.

I have never seen the inside of phono before, but two things don't seem right are the magazine never moves and when the "service scan switch" is flipped to "scan" the turntable is the only thing that spins.

Prior to ordering the manual I had only checked continuity of all the fuses I could find (at the time) and lubricated the "gripper spider" (from the exterior) with some oil. I was able to turn the knurled end of the gripper motor by hand but not with enough force to get the gripper to move a great deal.
I had broken enough things in my youth to know not to do anything rash.

Any direction you can give will be met with genuine gratitude. Thank you!

[jukenorman]

If you look at the drawing of the credit accumulator assembly on page 22, something will have been done to the accumulator reset coil to prevent it removing credits from the master ratchet to enable free play. The persistent hum will be from the latch plate solenoid which will be permanently energised because of the free play modification.

When making a selection, a pin should be moved at the point when the current limiting light flashes (although the lamp plays no part in that circuit). If you move a pin manually, does the magazine rotate? If not, this is probably related to the issue with service scan switch (poorly motor maybe?) It looks like you have a few things to deal with but the manual has shem-a-grams showing which circuits are made for each sequence in the operation. Deal with one problem at a time. There are stickies covering common problems and there will also be quite a lot of relevant info in previous posts on the forum (440 and similar models).

Norman.

[kestrels]

Thank you, Norman. I will go one step at a time and try manually moving a pin as well. The phono belongs to my neighbor and good friend. He's really hoping we can get it running again. Our analysis will be kind of slow moving. The good part about that is it gives me time to read up in between investigation. It's gonna look a lot more familiar to me since looking through the manual.
That credit accumulator assembly drawing looks pretty intimidating : )

[Ron Rich]

Have you l@@ked at the sticky on this subject, above ?? Ron Rich

[kestrels]

Ron, to be honest I'm not sure what a sticky is or at least how to get to it.
Nevermind! I just found your explanation

[Ron Rich]

Have you read the "Hi Newbies" post in our FAQ's section, and / or, the posts at the top of the "user introduction section, as you were asked to in a PM ? -- both explain the "stickies". Ron Rich

[kestrels]

May 4, 2022 14:21:03 GMT jukenorman said:

If you look at the drawing of the credit accumulator assembly on page 22, something will have been done to the accumulator reset coil to prevent it removing credits from the master ratchet to enable free play. The persistent hum will be from the latch plate solenoid which will be permanently energised because of the free play modification.

Norman,

Found it, (page 22)
I was looking at the parts page 36-37

Tomorrow will be my first chance to look at the 440 since reading the manual and talking to you guys.
It belongs to my good friend and neighbor.
We are both retired firefighters so I'm hoping he doesn't try fixing it with his axe before I get over there. (Just Kidding!)

As far as the hum that I had heard, I found that location in the manual under, "keyplate and switch assembly #44955-A".
Particularly from what is listed there as the "keyboard solenoid #43318". I'll focus on the credit unit for now, just seemed strange to have something constantly energized but then again I'm completely new to this stuff. 

Thank you,
kestrels

[Ron Rich]

Keep reading-- you'll figure out why it's "humming" ( this is NOT good !! turn power off-do not leave it humming !)! Ron Rich

[kestrels]

After visually checking the credit unit assembly on this 440, I wasn't able to establish its free play modification.
Both mounting screws for the "subtract relay" were in place.
The reset pawl and spring were not removed or tied back in any way.
My knowledge of electronics is limited but I didn't see any obvious jumper wire and really wouldn't know where to look if that is part of an electronic free play modification.

The coin mechanism or slug rejector (sorry, da book is with the jukebox now), is clearly missing parts but a cable still connects it to the credit unit assembly.

I used my remaining time with the machine to clean the wiper contacts and contact rings on both sides of the selector drum assembly.

Before leaving I did a short power up so I could be more specific about the hum/buzz of the latch bar solenoid.
When the machine is first powered on the latch bar solenoid is energized but not buzzing.
I watched it engage during the power up.
After a selection is made on the keyboard, the write in arm moves to position and DOES flip the proper selection number on the drum. It is at that point that you hear the relay(s) and see the CL bulb flash in the power distribution assembly. The latch bar solenoid starts its buzz but nothing further happens mechanically. The magazine motor doesn't make a move. I shut the power off so that the latch bar solenoid would de-energize.

I powered back up to start over and try flipping a selection by hand rather than using the selector buttons as Norman suggested. Again, nothing further mechanically speaking.

One other thing. I had them out and both the magazine and gripper motors spin freely and the brushes look great on both of them as well.
NOTE: I didn't bring a multimeter and I don't own a DC power supply

Any suggestions would be greatly appreciated.
Thank you, Neil

[Ron Rich]

Hi Neil,
Watch the credit wheel-- is it moving "down" on tooth when the sub relay energizes-- it should ! If so, run it down all the way-- latch solenoid should NOT be energized at this point. READ our FAQ's post on "how a jukebox works", and on "coils-solenoids-ADJUSTMENTS".
Ron Rich