Phonoland

My Dad bought an AMI Model A Jukebox a few years back that is not functioning. I thought it would be cool for Father's Day to try and get this working for him. I know little about jukeboxes so I'm working from a deficit. What I can say is it does power on when plugged in and turned on. Most of the lights light up.

As for the mechanism, when the power is on, the turntable spins but that is about it. I have some knowledge about electrical and mechanical systems from working on classic cars and whatnot. When I push the track selection buttons, I can hear a solenoid or switch click, but no movement of the record selection arm or anything else....just a spinning turntable. Is there a good write up on an AMI Model A somewhere online that would guide me on diagnosis and putting all systems/parts thru a check?

I have a service manual that was bought off Flea-bay. It has wiring schematics, but not much in the way of diagnosis procedure. I know the limit of my skills/capabilities which is why I was looking for other resources for diagnosis. I can tell the manual was written for a technician that had all the requisite knowledge of the inner workings of this unit and the manual was only a "roadmap" if you will, for every circuit.

One thing that has me confused is this is a Model A, commonly referred to as "The Mother of Plastic" jukebox, but the ID tag inside the cabinet says it is model # 500. Perhaps that is the the model # for just the record playing mechanism and not the whole unit?
Thank you in advance.

Hi Matt

The 500 refers to the mechanism type. The Model A is indeed referred to as "The Mother of Plastic"
It has a very easy and simple circuit that you should be able to follow, just read the manual fully a number of times before you do anything.

Regards
Alan

Alan Hood
ami-man
UK

Hi Mattt,
I would strongly advise you to "pull the plug" on that phonograph, and check the following before doing anything else:
L@@K carefully at all "cables", or "wires" in it. They used a "zip cord" (aka lamp cord) in this, and a few later models that was VERY prone to loosing it rubber coating. This MUST be replaced first !!
After that--it's a pretty simple 24 dc volt circuit that powers the mechanism (except the turntable motor which is 117vac). Check the power supply--check fuses for correct type and size, and you should have it running in "no time"--
Ron Rich

Ron Rich, thank you for the suggestions. I had a look at the wires this morning, and there is at least one that is kinda crusty and will be replaced.

As for your second point, that leads me in the right diagnosis direction and explains why the turn table spins but everything else is dead. It is interesting to me that the complete record player assembly is not run off one power source, but I'm sure they had their reason. First order of business is to check the 24v transformer for power. I haven't ID'd the player assy transformer yet, but I do see a transformer down on what I think is the amp assy. The manual should come in handy to ID the 24v transformer. Thank you again and I look forward to any further suggestions and guidance.

Yeah..."no time" is very subjective

I've spent some time reading the manual and becoming familiar with some of the parts inside the cabinet. I haven't been able to definitively ID the 24v transformer that runs the mechanism, but the mechanism is definitely not operational.

What I'm seeing is the mechanism is mid-stream in it's process. The manual tells me that the arm should default to over by the record rack. The arm that places records on the turntable is between the record rack and the turntable. I have hit the "reset" button on the control box to no avail. What I am calling the control box is behind & below the turntable and has 5 cable plugs going into it. There is a red reset button on top. Also, turning the jukebox on and off does nothing as far as re-setting the mechanism. I'm looking for suggestions on what may be causing the mechanism to be stuck mid stream and/or what the next course of action should be. Thank you in advance.

Matt,
"Hitting the reset" is NOT what should be done !!
You might check all fuses--replace only ONCE, with the correct type/size fuse, if one is blown. If one has blown, that will tell you which circuit is having a problem--
You might also attempt to turn the gripper motor by hand and get it over the record rack--the gripper is probably 'frozen', and will require dis-assembly, and proper re-lubrication. Ron Rich

In reading the manual I have, hitting the reset or cycling the juke off/on is what it suggests to reset the mechanism. I only see 3 fuses down below on the power distribution box. Are there others besides those 3? I've checked all 3 and they appear to be good, but I will check again because I do remember them not looking like a normal glass bullet fuse.

Hitting it ONCE, is OK--but I would not do it repeatedly--
Don't recall, but your manual/schematic should say if there are more fuses --
Did you check types, and sizes ? Ron Rich

Hitting the reset button has zero effect. It's as if the reset button is disconnected or the system that it resets is completely dead. There is no click, buzz, hum, nothing nada. The track selection buttons on the front give an audible click when hit. The reset button, nothing.

I'll have to take another look at the 3 fuses I saw. Are they normal glass bullet fuses or are they different from the automotive version that look similar? What is the best place to source replacements? Thanks again.

Hi Matt,
I do not recall what the "reset button" re-sets ? Would need to see schematic, or the button itself ?
The fuses generally used in post WWII phono's, are either Buss Brand AGC types, or Little fuse 312, types. These are "fast blow types and interchangeable between brands. Also used are the "slow blow" types. Buss labels these as "MDL", while Littlefuse, calls them "313"-- SIZE and type are very important--NEVER use a larger size-, as you will have NO protection---
(Today, there seems to be a new supplier every time I order fuses--either Mexico, or China, and they tend to use the Buss designations)
These fuses can be purchased at any good "electronics store" and many hardware stores, as well as "Radio Shack", in limited sizes/types.
HTH, Ron Rich

I checked the fuses earlier, all 3 are good. I didn't see any additional fuses unless they're hidden elsewhere on the unit. Here is a pic of the "reset" button.....red button on the black relay box.

Any other AMI gurus here that wouldn't mind weighing in?

Hi Matt,
I am not sure--but I think that switch is the (record) reject, aka, cancel switch.
When you say you "checked the fuses"--were any of them larger then what they were supposed to be ? Did you use a meter, or test lamp to do so ? If they truly are/were, the correct size, type, and good, you will need to check all voltage readings next, to determine which circuit is failing--Ron Rich

Did you notice / check the position of the 24v power toggle switch on the BACK SIDE of the main control box in the lower left of the cabinet? Have to reach around back to feel it.

cg591 wrote:Did you notice / check the position of the 24v power toggle switch on the BACK SIDE of the main control box in the lower left of the cabinet? Have to reach around back to feel it.

Thanks for alerting me to that switch. I wouldn't have known it was there since it's hidden. It was on(up). I have determined the 24v system is functional.

I made a little progress since my last reply. As I mentioned earlier, the record changing arm was stuck in the middle of it's cycle. I noticed there is a splined shaft sticking out of the non driven end of the motors, so on a hunch I tried turning them. They do turn and run the gears/chain. Once I moved the record changing arm to the down/playing position, I could manually put the needle arm on a record and it actually played and made sound out the speakers. Possibly the next thing to diagnose is that once the song comes to the end, the arm does not lift or it doesn't stow the record back in the rack. I'm guessing there is some system that can should set this process in motion. The record/needle just stays at the end and continues to spin.

After a bunch more tinkering, one additional thing I was able to make the system do was to stow the record in the rack and "turn off." When I had a record at the end of a song, and just continually spinning, I hit the "Cancel" button on the power box(lower left corner of cabinet where main power & light switch is located). The mechanism went into action, picked up the record and stowed it. It should do this automatically, but it only does this when I hit the "Cancel" button. It does not do it every time though.....it's kind of hit and miss after several tries. The first time it did it, I could tell the mechanism is a bit sticky because the gripper wasn't able to close enough to grip the record. Another time, it got half way thru the process and stopped the record changing arm mid stroke. I could hear a buzzing sound, so I reached for the splined end of of the motor and I could feel that the motor was trying to spin, but something was preventing it from spinning. I unplugged the cabinet to cancel so the motor didn't burn up. Is the lube process for the gears, chain, mechanism something that is done by total disassembly, or just hitting the correct spots with lubrication? What is the preferred lube?

Thanks again for all the assistance so far....making progress.