Wurlitzer 3110 main motor question

Hi,

I have a lady that calls me about once a year with problems with her 3110 Wurlitzer. This time she said the machine was making a "grinding" sound and wouldn't pull a record. I opened the back and the arm that contacts the pins was pushing hard on a pin like it hit it, but didn't switch over to cancel the pin and reverse the motor.

Cleared out all the selection pins (pushed them down) by hand and turned the power on. Lights up. Make a selection on the keyboard, pin pops, but nothing else happens.

I checked all the fuses I could see visually, (didn't take the meter), and they seemed ok.

Any ideas on where to start on troubleshooting this one?

It's a long drive over there and I don't want to make more than one trip. Also, is there a way to check the motor using a meter?

Thanks,

Mark

Hi Mark,
If you are still there--check the two record lift arms--be SURE that they have gone down far enough to clear the basket--the check "load-run" switch--must be in "run" position--If that 's all OK pull "back" on the crank arm that hits a released pin, motor should run, and place one record on the TT. If it does NOT, check the Micro Switch, that is activated when you pull on the crank arm. Check voltage to the motor at the transfer switch.--if it does, allow it to play the record and see if it will remove the record and work. If it removes the record, release another pin, and see if now working. If so, "clean" the transfer switch . Ron Rich

In addition to Ron's suggestions, find out if the motor shaft is turning. I suggest taking a known good motor if possible.
Those gearbox motors were not as rugged as the old DC motor-gear types for which that mech was originally designed.

As a rule, I always weakened the arm lift springs and made sure the lift arms did not bottom hard against the stops. Make sure the mech is properly oiled There is way too much strain in that machine and I remember seeing several of those AC motors with broken gears in the service bays over at Al Simon corp.

Rob-NYC

Hey guys,

Thanks for the feedback with limited information.

The lady replaced the manual and I brought it home. While I was there I checked all of the fuses and they were all good. I popped a pin and slid the amp out and manually activated what I'm pretty sure is the override relay (electro magnet under two switches) inside the amp. (probably a no-no.. sorry) but this started the both motors which went through it's normal cycle, picked up and played the record. I hit the cancel button and it removed the record correctly.

I am not super handy yet with a volt meter, so it this is the wrong way to do this let me know, but i set it to DC and checked each side where the power comes to the magnet. I put one probe on the connection and grounded out the other on the case and it showed voltage (I think.. I mean the needle moved). On the other side of the relay, same method ... no reading. Between the two contacts ...no reading.

I don't know enough to understand if those readings are even relevant.

So does that mean the relay is bad? ... what are the other possibilities? Because I really would hate to go to the trouble of replacing it only to find the problem was elsewhere.

BTW, this is probably the cleanest, sweetest sounding machine I've worked on to date. It's been in the family since the early 70's

Thanks,

Mark

Hi Mark,
Sounds as if you have proven the relay is good--meter would only "read" on one of the contacts, if it were open--
Check the "Override switches" on the "Electrical Selector". They often get "dirty", and must be serviced ( see above sticky-"contacts--how to clean") Ron Rich

Hey Ron,

Your advice is awesome so don't take this as me doubting you, but unless there's some way I don't know about, those override switches are really hard to get to and this lady lives 45 minutes away, so I'm not real excited about the prospect of open heart surgery in her living room.

This is a super clean box. And my question would be what are the odds that all of the override switches would fail at once? Quite possible I don't understand how the circuit works. I thought they were open at rest and then one of them was closed by the wobble plate. So wouldn't it stand to reason that while one section might not work, the others would?

Again, not doubting you, but if there's anything else I can check before taking the drum apart or if you know an easier way to clean the switches, I would appreciate it.

Thanks,

Mark

Hi Mark,
I have seen numerous instances where all three of the over-ride switches have failed--unfortunately, I have never been able to "clean" them with out removing the ES--almost a MUST do, on a 3100--don't know about a 3110 ?? CAREFULLY, follow the service manual here--not too hard to do, except that your back, if like mine, will be sore, afterword ! You can "prove" this by "shorting out" one or more of them--If I remember correctly, these are either a "plug in", or they run thru the wipers on the basket--if the later, I have seen the wires "broken" there, before--- Ron Rich
P.S. Yes, you understand correctly.

Hi Ron,

As always, forgive my verbiage. I am novice with the electronics stuff.

I finally got back to this machine today and I am still stumped. Let's start from scratch with the readings I took today.

First the machine will cycle and play if I engage the switches on the override relay manually. Everything works perfectly. If a pin in the selector drum is up it catches, loads the record, plays. When I hit the reject button it cycles as it should until I manually release the switches on the override relay.

If no pins are up and I manually engage the override relay the mech rotates and the turntable motor comes on, but with no pin up it will operate until I release the override relay switches.

I had my meter this time and I double checked how I should be measuring.

There are two connections on the relay that I assume control the magnet that activates the switches attached to the relay.

With the power off and the meter set to OHMS I read a 0 between these two connections.

With power on and no pins up I read 30V DC on one side and -30V DC on the other side. With pin up, it reads the same.

I removed the drum and checked the continuity between the override switches. No breaks there.

The manual does not have an electrical sequence but checking a different manual it seems like getting voltage on both sides at rest and when a pin is activated is not what should be happening. I'm noting that the transfer switch is a part of this circuit.

I cleaned the override switches.

What am I missing here? If I can't get this fixed, is there anybody out there that I can send it to?

Thanks,

mark

I was trying to see what the sequence was on a working machine I have here.

At rest if I manually move the override switch, the record motor starts, but the mech does not turn as it does on the faulty machine and the "good" machine tells me that it does not like me manually operating the switch on the over ride relay.

Is the transfer switch a possible problem? The bad machine has two wires from the transfer switch that dead end into a plastic connector that looks like it should plug in somewhere, but I don't see a female counterpart anywhere.

Thanks,

mark