Wurlitzer 3117 selection (latch pin) issues

Huh, thanks for the background info, guys. At least now, if/when I get a stepper and have issues, I know what to look for.

Thanks for the additional info; I learned something new.

To answer Ron's question, it's a black gear. It came from a later model Wurlitzer stepper; it's not a 'new' replacement part by any stretch of the imagination.

Back to the issue at hand;

I confused the issue a bit in my last post.. When selecting from the keyboard, an *incorrect* latch pin is being released. R4 releases F4, A2 releases L2, etc...

I'm getting the sense that the stepper is somehow at fault here.

If I trip a selection directly from the pinbank, the selection process works as intended - (releasing latch pin R4 plays selection R4, A2 plays A2, etc.) It's only when making a selection from the keyboard that the incorrect selection is being played.

I think I can eliminate the backstop pawls as a potential trouble spot, as the jukebox functions precisely as intended, with the exception of the selection / write-in sequence...

Thanks again.

Regards,

Matthew

Matthew,
You are correct--somehow I must have miss read it--I thought you were getting the correct pin to release, but it was playing the on 180 degrees away--which is the backstop problem--
I do not believe this problem is stepper related, as it should not really be "in the circuit" when not in motion--what happens if you select from the wall-box ?? Just a guess, by chance, do you have plugs reversed??

Ron's suggestion of reversed plugs from the junction-stepper to memory is a possible cause IF the error is consistent. Since this is a hideaway we don't have a keyboard to try out.

So, if not simply reversed plugs it is either wallbox or stepper itself.

If possible, place the wallbox where you can closely observe the stepper while making selections. First, try the selections that create the largest number of pulses. that is V-0 or V-10. Do the stepper wheels appear to advance with each 'clap"?

Next: Select U-9 and hold down the center coil either with a finger or carefully wedge something so that it does not release the stepper wheels when the pulses end. At this point there should be only -one- more step that the wheels could make; that would be to V-0. Try this several times.

If selecting U-9 always leaves one more stop on both wheels -the stepper itself is operating correctly and you must look for reversed plugs as Ron suggested.

If some other result shows up, examine the following:

Wallbox: look for broken wires leading to the contact wafer that the wiper rides around on. If you have a continuity meter analog or digital, connect it between the signal terminal and wallbox common (usually it's chassis). Turn the wiper --in the normal direction-- and note that as the wiper lands on each contact you see a low resistance connection. Alternately, you can connect a 28 volt bulb between AC input (approx 25v) and the signal terminal. It should blink at every contact as the wiper turns. The Wurlitzer steppers are tolerant of poor contacts in the wallboxes only up to about a 150 ohms.

We can go into stepper tests later.

Rob/NYC

Success... Finally!

Well, I must say a very heartfelt thank-you to both Ron Rich and Rob-NYC for their invaluable advice.

As it turns out, I did indeed have two plugs between the control box and the selector reversed. I was 'fairly' certain I had marked the cables correctly prior to removal of the control box / stepper but it seems this wasn't entirely true. Once the plugs were swapped around, all selections started working as expected.

Thanks again.

Regards,

Matthew

That is great! How about a couple of pic's?

Also, make sure to -thoroughly-- oil that mech. There is a lot of excessive strain, particularly in pulling down the lift arms.

Rob