Wurlitzer number solenoids sticking in down position

Hello All! Brand new member here. I've acquired a Wurlitzer 3300 and for the most part I've got it working fine with a new needle and brand new capacitors in the amp.

My last bit of troubleshooting is to address the sticky number solenoids. At first, I thought they might be gummed up with something, but they are all clean. Then I thought maybe the springs were tired after all these years and weren't strong enough to counter-act the magnetic pull. Upon really looking closely, however, I've noticed that the solenoid pins are getting wedged into the mechanism, enough so that I have to pry them up with a flathead screwdriver when this happens (which is often).

I suspect this is a problem that other people have already encountered. I'm crossing my fingers that I can make some sort of adjustment without having to remove the selector mechanism from the machine. So far, I've been lucky to have only had to remove the amp.

Any ideas???

Thank you in advance!

It sounds as if you are speaking about the letter, rather than the number coils ? If so, do you have the service manual? If not, see the post above for whereto find it. If so, there is a detailed adjustment for that section in the manual. The only hard part about removal of the electrical selector is, that on the 3300 models it sits so low to the floor, you may want to "jack-up" the phonograph to remove/install it . Be sure to follow the instructions and NOT remove the screws it tells you not to remove !! Ron Rich

https://postimg.org/image/v3uwp11gr/

Here is a photo of the stuck number 7. When the number 1 sticks, I can get a photo from the underside as well.

From your pic it looks like the the two microswitches are in the relaxed position. But the actuation screws look to be still closer to the switches than they should be after the punch and the search motor reverses.

---Is the search motor reversing after the punch to release the number vane?---- If not, one of the microswitches may not be setting up the reversing relay in the junction box, or the contacts on that relay my be pitted or not closing properly.

Rob-NYC

Above is the stuck number 1 solenoid, and in the photo below you can see how the solenoid is wedged in the machinery.

I've also noticed that when you hear a distinct buzzing sound in the beginning, the solenoids usually release. When you don't hear that buzz, they usually stay wedged in the machine.

Ok, that is different. What is happening is that the rocker is getting wedged inbetween two pins.

A week or so back I answered some questions about the carousel mech:

Problem spots are:

-Over time the indexing of the rockers (hammers) becomes a bit sloppy, the hammers to get wedged between two pins. Sometimes this can be dealt with by tightening-up the clearances of the nylon guide rollers that center the rocker-gear plate. My solution was to widen the hammers by placing aquarium airline hose around the ends of them. Check also that they are not bent in either direction.

-Excessive force used to pull down the lift arms. I do a careful alignment of the lift arm rollers to minimize friction and then just stretch-weaken the lift springs. I reduce the lift force from several pounds to approx 10-12 oz for the 200 mechs and 6-9oz for the 100-104.

-I am not wildly of how wurlitzer used the hard-stalled search motor to index the rockers. Eventually, this breaks the gear box, which, BTW should be oiled. Some people drill out the rivets, I prefer to make a 1/16 hole in one corner of the gearbox and insert a needle oiler.

-There are leaf switches in the keyboard assembly that are a bit too weak for the purpose and must be re-formed slightly occasionally.

-The tonearm is a bit massive and has rather crude bearings...but...whatever.

-The keyboard-grill wash fluorescent lamp is a b---- to replace in that model. But again.....

If the machine has the original Sonotone pickup (8T or 8TA) -plan on replacing it. I always used a Pickering magnetic and added or built a preamp.

Rob-NYC

Rob-NYC wrote:Ok, that is different. What is happening is that the rocker is getting wedged inbetween two pins.

-Over time the indexing of the rockers (hammers) becomes a bit sloppy, the hammers to get wedged between two pins. Sometimes this can be dealt with by tightening-up the clearances of the nylon guide rollers that center the rocker-gear plate. My solution was to widen the hammers by placing aquarium airline hose around the ends of them. Check also that they are not bent in either direction.

Rob-NYC

The tubing trick sounds good. Do you happen to know the size or gauge of the tube that fits best?

I just used whatever spare aquarium tubing we had left over from when we had a tank. I open it slightly with a needle-nose pliers to get it to fit snugly. Cut it right to the edge of the hammer so that there is no metal protruding.

If you have more questions, I'll be back later.

Rob

I've tried a few things that haven't worked so far. I've taken a short video of the solenoid working and not working:

Jamming solenoid plunger. For some reason, the plate doesn't reverse, so the plunger doesn't return to the up position. It stays wedged in the machinery:

https://youtu.be/Huf7mz64UA4

Working solenoid plunger. The plate reverses, allowing the plunger to return to the up position.

https://youtu.be/kzalZm49PAA

I don't think the addition of tubing is going to help in this case--
It "sounds" like the reversing switch MAY be set too tight , or the stop switch is "flaky" --there should be some time between the points that the stop and reversing switches are activated--did you check both the stop and reversing switches as explained above ? Ron Rich

I've read section B of the manual a few times now, and it's only beginning to make sense, so I haven't checked any of the switches yet. I'm not even sure what to look for, or if I need to take the machine apart to get to it. I'm hoping I can make the adjustment via the two hexagonal bolts near the number quadrant.

I removed Relay 3 and followed some instructions via the manual, but I may need to go further. I'm a chef, so this isn't what I normally do at all.

I've screwed in the hex bolt on the reverse switch and it seems to have cured the problem for now. Makes sense, since the number quadrant wasn't always backing up enough to let the solenoid plunger release. Thank you for your insight!

Your video shows a different problem than ockers getting jammed.

The number quadrant assembly backs off by spring pressure, The reversing of the search motor simply reverses the the stall pressure on the number vane.

Make sure that the number quad moves reasonably freely within the limits of its forward and backward stops. Old oil and dirt can make the center bearing sluggish. Check that the return spring is there, it is attached to a hook near the coil farthest from the microswitches.

Check for proper reversing of the search motor. Press in on one of the microswitches. I believe it is the top one. The search motor should reverse the rocker plate. Press slowly so as to be sure that the motor stays energized as you press the actuator all the way inward to it's limit. Be careful when adjusting the actuator bolts on these switches. If you turn them too far in the quad will hard stall against the switches instead of the intended stop on the casting. this can lead to the punch occurring too soon and causing a rocker to jam between two pins. I adjust the bolts to leave approx 1/32 in of freedom on the switch toggle when the quadrant is manually pressed against the hard stop.

Rob