Help with Wurlitzer 3610

Hi. I offered to check out a friends Wurlitzer 3610. I do these silly things from time to time.

Anyway, the system wasn't doing much until I discovered the letter series switch was out of adjustment.

Now, when I make a selection, the selection accumulator magnetic arm whirls around but no latch pins are popped up. Then the box just sits there and stares at me.

If I manually engage one of the latch pins and then depress the override solenoid, the record carousel will move to the selected pin, and play the corresponding record.

After the record is played, the record arm returns the disc, the carousel makes 2 full revolutions and the magazine locking arm engages.

I suspect I still have a problem in the selector switch assembly but so far, I have not found it.

I have a service manual and a wiring diagram which have been very helpful and the sequence steps on the backside of the wiring diagram have also been very helpful but I seem to get all muddled up when I hit steps 5 to 7 of the standard selection sequence.

I was also wondering what the dotted line ‘stepper jumpers’ are supposed to do. I don’t see them mentioned in any of the service procedures.

If anyone can point me in the right direction, I would surely appreciate it.

We all have those "silly daze " !!
Sounds like typical contact problems on the "write in fingers" that fly around the pin assembly when the keyboard is energized.
Also, could be a poor contact(s) in the keyboard itself---
The "stepper jumpers" you see in the schemo, are necessary only if no stepper is installed in the phono.
HTH,
Ron Rich

Well, I’ve learned much more about juke boxes that I ever wanted to over the last week.

It seems most of my problems are centered in the keyboard selector switch mechanism. I spent a few hours painstakingly performing the 4 pages of adjustments to the letter and number levers and switches. I even dug up my old feeler gauge set to check the 1/64”, 3/64” and 5/64” tolerances.

The result? It works some of the time. When it doesn’t work, the solenoid seems to reset too quickly and the selection accumulator doesn’t activate. It seems to work more often if I select a number first, then a letter.

Before I made the adjustments on pages 2B to 5B, I tried to clean all the switch contacts using tuner cleaner and a mild abrasive paper.

On a side note, I am concerned about for the latch solenoid. Someone before me set the unit up for continuous song selection, although I don't know what modification they made. The select light is always lit. And, the latch solenoid is always engaged. The solenoid doesn’t seem to mind it but the 85 ohm resistor in series with it gets bloody hot.

I’ve observed a second problem in that when the switch mechanism is working, the unit will play odd number songs all the time and even number songs occasionally. The side 2 switch does seem to see the pin as there are some clicks in the machine as if something was activated, but most of the time; the magazine makes 2 full turns and then stops at A1.

Any insights and suggests are always appreciated.
Thank you

Well, what can I say, except you should have asked prior to "making all those adjustments", as 99.99999% of the time, unless someone has "messed" with them, the factory adjustments are correct--they do not "change", with out help. The main reason people believe they need to "adjust" something is "dirt". Cleaning the keyboard, and oiling to moving portions, usually restores the operation with out adjusting anything. It would be my advise that you remove the keyboard, and wash it with hot soapy water--ammonia, helps too. Remove the coil while doing this--dry totally, and oil the moving parts with 20 wt. ND oil. Do not get anything on the slide contacts themselves. Use no "contact cleaner" that leaves any type of "residue". Then replace the coil, and re-check/re-do, all adjustments--All "open blade" type contacts need to be free of burns/pits, and burnished lightly using a burnishing tool, not "sandpaper" of any type.
As for the hot resistor--if that bothers you a 10 watt unit can be sub'ed.
If the phono uses a mechanical "Play-rac", for a "credit unit"- "accumulator", I would assume someone has flipped the credit removing spring to the opposite side of the credit wheel--a common practice. If it uses a "BO/AC", someone's jumped the key switch closed--usually with a "dummy plug"--
On your "second note"--I would assume the read out switch for that side is defective--or the actuator is not hitting the released pin ?
Ron Rich

Ron,
Thanks for the insight and suggestions.

Regarding the washing process you recommend, should the keycaps be removed or can they be submersed? If they should be removed, is there a preferred method to preserve the aging plastic

How about the rest of the selection board, less solenoid? There are a few open contact switches and a few closed ones and I wonder if they would survive a good dunking.

The reason I focused on doing the adjustments to the keyboard selector was because the switch contacts were bent in odd ways, not coming straight out of the phenolic blocks. It looked like someone had messed with it over time and so far, most of my problems seem to be emanating from that module.

I did burnish the contacts on the open switches but I was wondering if I should attempt to dismantle the switch blocks and straighten out all the contact fingers.

The service manual shows a connector on the selector board for the harness. On this particular machine, the harness is hard wired to the selector assembly which makes the washing problem a bit more challenging.

Hopefully this will give me a more consistent result. Right now, the switch selector works about 1 out of 4 tries. But it does work. Sometimes. I must be very close to the edge on a few of the specs.

Thank you again for all your help.

King,
Sorry-I am not familiar with the "keycaps" on that model--
Open bladed switches should have no problem surviving that wash procedure--
Ron Rich