Rockola reset selector button

Hey all, first time posting, first time juke owner! I recently acquired a Rock-Ola 429, have restored it to working order. Am still going to re-cap the amp just for safety sake, and make a few cosmetic adjustments.

The only issue I'm having with it is the reset selector button will not work (not the record cancel, the button reset). It is getting juice, and I can't figure this out to save my life. Everything else works, all other selector switches work, except for the reset button. The service manual doesn't really mention the reset button, and I'm not having much luck with the schematics on it either.

Have cleaned the 21pin connector just to be sure, didn't help.

Any help would be greatly appreciated...thank you!!!

Hi Bossman,
If you purchased the service manual, from a "legit" source, as shown above, it should have had a schematic included in the "package". This is where one would need to look for a problem of this nature.
I have never experienced such a problem, but I ASSUME that the reset button ("ground"?) pulses the selection system when pressed to reset it ? OR, perhaps it's in series with the selection system and opens the circuit, when pressed ? To determine which--see if it closes, or opens, when pressed.
Ron Rich

Ron, thanks for your reply...

When I purchased the box, the guy had already had the service manual and gave it to me. It is a complete, legit manual. Although I haven't found much in the way of the selector buttons as far an electronic schematic goes there are many diagrams of the entire mech in action along with the selector buttons...but I'll take another look too.

From what I was able to dope out looking through it, the reset button is in series with the other selector buttons, and "should" open the circuit (disengaging the latching solenoid) when pressed. However, there is a capacitor that has been installed in parallel with 2 leads going to the solenoid. This looks to be a replacement cap, I can definitely see where old leads where cut and the newer cap installed. Everything else with the selector works correctly, so maybe its out of tolerance. The latch solenoid disengages the selected buttons once the write in arm has finished its cycle, but when that happens the circuit overload bulb does light up very briefly. Also, there's always a steady hum coming from the latch solenoid, even when there's no credit on the machine.

Hopefully this sheds some light...thank you so much!
bossman71_ky

Bosman,
I was thinking of RockOla's later latch bar circuit when I wrote that--wrong !!
Once again, only guessing as I do not recall ever having a problem like this --
I believe power is supplied at all times to the solenoid, but ground is only supplied when credit is established. If I'm correct, that means that reset button is in series with the contact in the relay that supplies the ground( relay is released when you see the ballast lamp light). I would check that switch, to see if, in fact it's opening, when pressed. It's also possible someone subbed a different pricing unit in that phonograph, and there is another ground path--especially suspicious since you say it "hums" without credits ! ( are you 100% sure the hum is from the solenoid?) Capacitor --are you sure that's a cap ? I do not recall ever seeing that either--a large resistor is common, but no cap, as far as I know ?? ( I well can be wrong here also !) -- You are going to hafta see the schematic--and figure it out--
Ron Rich

Thank you Ron,

That sounds about right...the circuit is completed when credit established, but the solenoid stays energized all the time. And the switch operates fine, checked continuity last night, on/off as it should.

That leaves the cap, its a .22mfd orange drop, 1600vdc. I'm sure the hum is coming from the solenoid, I can wiggle the arm and it comes and goes when I do that. I'll pour over the schematic when I get home tonight and see if I can track this down...I'm like you, everything I've seen has no other component in parallel with the solenoid there, or if there is, it's a resistor. Also, if there is a record playing and I make a selection, there is an audible pop from the amp when the buttons are released...maybe that helps to further identify this?

I'll also look over the credit unit, I've not looked at it that closely, but I'm pretty sure its original to the machine.

Thank you for all your help!!!
bossman71_ky

Hi Bossman,
The cap, I would think, is there to suppress the "Pop" when that solenoid is released.
I have no ideas on the other problems--? Ron Rich

Ron,

Could it possible there is not supposed to be a cap there at all? I'm not seeing any component in any of the diagrams that I've found thus far...

Thank you!
bossman

Anything's "possible" ! It's also possible the factory added it, but it did not do so in time to be noted on the print ?
Idono ! Ron Rich

Update on this issue:

I removed the cap across leads at locking solenoid...no change in operation, and it actually improved the pop that was coming from the unit when a selection was made while record is playing.

I discovered a leaf switch that was not closing when credit was applied, so I bent the leafs to make contact...but now, after having done that, if I press a number first instead of a letter, the write in motor starts to spin, makes 1 revolution, kicks button out, and empties credit. This didn't happen before. Also, the reset button still does not work.

Any thoughts? I'm thinking I've got a stray ground issue somewhere in the button bank...

Thanks all!
bossman

Bossman,
Check the service manual--hopefully the leaf switch adjustments are shown--you may have a"timing issue" with them now ?
Also, read above "how to clean switches".
Ron Rich

In my looking through the service manual, I discovered that I'm missing a page...page #25, which ironically, is the exact page I need to help me with the issues I'm having.

I hope it wouldn't be too much to ask, but if anyone has a scan of just that page they could provide me, I would greatly appreciate it...otherwise, I'm going to have to buy another service manual. If anyone has this, please PM me and let me know.

Thanks all!!!
bossman71

Bossman,
If you purchased that manual from one of the "legit" sources listed above--you should contact seller for that missing page.
Ron Rich