The wife's Rock-Ola 451. Suggestions?

[empireofdirt]

(New member here)
Headline: The jukebox doesn’t work now. The turntable turns, the amplifier receives signal from the cartridge—both of those constantly, whenever it is just plugged in. I’m almost certain that both of these should be happening only when the unit is playing a record.

Thank you for having me! The story so far.

Backstory:

This was offered a few miles from us, and the price was low enough that I felt it was a reasonable gamble to take, as my economy-minded wife says she's wanted a jukebox, but has held off on the urge for over fifty years.

Today, the key came in from one vendor, and the service, parts manual and wiring diagram came in from another.

I got the front open, gingerly pulled all of the jostled records I could out of the unit and restored them to their slots (the previous owner had loaned this out to a youth group (!) before we bought. Red flag there) 

The rim-drive turntable started to work after I discovered a similar jostled problem. I reseated the turntable ring/assembly where the idler could do its thing.

I could get it to make a selection and play a record, successfully ran the audio up via the pot in the back. The gripper arm assembly could adequately pick and place a record but would not pick up the record from the turntable to return it to the slot of origin. I got the gripper to where it would do the right thing. I repeatedly checked its operation from the one selector slot that had given me a lucky break, and there was repeatability multiple times.

Dangerous Diagnostics:

At that point, I checked other slots and got one or two to work, then it quit functioning in the state already described—amplifier and turntable motor assembly always on.
Hitting Reset does nothing helpful. Pushing what looks like the red-stick TV-style circuit breaker (1.40 amp) inside for mechanism stops the platter momentarily, starting again immediately when released.

Choosing the selection via the key switch buttons that allowed me to play a record now produces a flash behind the fuse panel—I believe it to be a momentary impulse to the bulb that is item #37 on the diagram.

So: There is some logic that is not working or has gotten out of order with the unit now (?) but we have witnessed that it has all the electronics to play records, and I am hopeful and fully open to suggestions before I have to do a full Vulcan Mind Meld with what factory-printed information I have in front of me, as this is the first jukebox she has had.

I will add that, per the late Mister Ron, this unit has been made "illegal", in that it seems to have the coin mechanism but there is no need for coin insertion for the unit to work.
After the fact, I've discovered the main 6A fuse has been replaced with a 10 at some point. Dunno if someone needed the overamperage or just got lazy with a replacement.

Thanks for any guidance you can give us.

I am posting from Johnny Cash country, not too far from my hometown of Music City, Tennessee, which has tripled in size in my time.

"...you could have it all, my Empire of Dirt..."

[jukenorman]

Hi Empire of Dirt,
Welcome! There's quite a lot of info in your post and you have made a good start by arming yourself with documentation! The "sticky" post "How a Jukebox Works" is well worth studying if you are a novice and also bear in mind there is a lot of useful information already on the forum replying to people in similar positions to yourself. The basic mechanics of the Rock-Ola jukebox operation doesn't vary much between models. There will be oiling ("sticky" post on this also) and cleaning required.

My personal recommendation would be to position the gripper arm over the magazine - you can turn the gripper motor manually using the knurled knob if need be - and start by ensuring that the magazine motor runs. Then proceed dealing with each problem as you encounter it. The Rock-Ola manuals do have very good schem-a-gram diagrams showing and explaining each operation.

Best of luck and I have every confidence that you will be successful.


Norman.

[empireofdirt]

Thank You Mister Norman!

There might be considerable time elapsed between updates, because I intend to digest all of the material at my disposal to the best of my ability before asking *all* my n00b questions. I am quite aware of my need for 'both hands and a flashlight' (and phoneAfriend!) in this endeavor. -And, to be fair, this one needs a thorough respectful cleaning.

Upon reading the 'how a jukebox works section', I realized I need a firmer grasp on the Taxonomy of all the parts and their Operating Sequences to get max utility out of the site. I've been going around on the forum and absorbing stories about burned and stuck coils under pushbuttons, worn brushes in the motors, open resistors and diodes, cleaning card edges and tightening individual Molex connections to get everything Flight Line Ready.

Similar to other last-century restoration endeavors, the concerns a half-century out include things with wearing surfaces, things that make electrical contact by friction fit, things that brown or fade under UV rays; grease that dries out, turns to wax or tar; rubber that dries out, or turns to goo; things with few substitutes if they needlessly crumble under a hasty or careless hand.

The joys of restoring the ballet of yesteryear's mechanisms, the durable designs undertaken by a generation of folks whose environment was slide rules, flattop haircuts, and the folks in the engineering department smoking at their drafting tables. The physical media aspect aside, today's version of any mechanism to handle records would be more cheaply accomplished by stepper motors, ribbon cables, sensors and optics on multi layer pc boards... individual surface mount components the size of a grain of pepper...none of it matching the beauty or longevity of these machines designed to keep working in the harsh environments of yesteryears' honky-tonks and greasy spoons.

(Id've been in trouble if I'd drug in an erratically functioning machine on my own recognizance, and The Meter would be running on its repair. As it is, I have permission for measured, thoughtful disassembly; to occupy a corner of a room with tool kits and cleaning rags, bags of disassembled parts, and evicted spider carcasses. This will not invoke the impatience and indignation that surrounds the flurry of activity proceeding with cleaning one of my typewriters, for instance ;-)

And I've always found jukebox mechanisms fascinating as well. The missing ST-8307 Permacel on the Top Glass horizontal currently provides a view into the mechanism that, even though this one is not styled to have all its automata on display, is nonetheless a modest joy to behold in of itself (if not as elegant as those of its mid-century forebears.)

[empireofdirt]

The Bride was not keen on getting a RockOla 424 "Princess" in shaggier condition for less, for parts, though we are but thirty minutes away from it. So my natural inclination to be "prepaired" for any situation has been externally curbed. (If it needs electronics, I guess I'll be getting them one ebay package of bubble wrap after another) Not germane to the discussion, merely an observation.