Rock-ola 448

Hi Guys,
I have found that cleaning this type swith with a pencil eraser won't always "do it". This is because there are more contacts on the back of the switch (that you can't see). The best method I have found is to use a non-residue solvent ( be sure it's "plastic safe"), first, then the eraser, then Deoxit.
I highly doubt this switch has been re-wired, or that it is the cause of your problem.
Do the write-in hammers attempt to fire at all ?
Ron Rich

Hi Ron,

I tend to agree with you regarding the switch not being the issue.
I tend to hate dirty switches, and I strip them down to get to the contacts you can't see, I have come across a few that have been faulty where the contacts have burnt through due to the contacts being loose.

Regards
Alan

Alan Hood
ami-man
UK

Hi alan, and all,
I once won a large bet with a "design engineer" over "dirty" switches. He worked for a major builder of switches and claimed that 1. An overcenter snap type switch ( which his company built and possibly invented) NEVER fails to switch as the same "plunger moovement place", and 2. It "can NOT bounce". Well I had a dozen or so of brand new ( made within the month) switches from his company, and they were all defective. We were attempting to use them in a timing circuit, and they would fail --some almost every time --others one out of ten or so times. He shouted (on the phone) that it was "impossible" for that to happen, so, I told him to get his arse on a plane, and I would either prove it, or pay for his fare, and dinner, out of my pocket.
Well, lets just say he purchased the tickets and both our (really nice steak) dinners --and claimed, later, after he took all my stock, that this bunch of switches was "contaminated". Ron Rich

Hey, guys.

I will give the switch a cleaning as suggested. I will also measure for voltages.

The writing happens fire very well and move the selection lever into play position.

Write in hammers*. Sorry, autocorrect fail.

OK--now you have me confused--what happens after the hammer moves the pin -- or does it not move the pin ?
Ron Rich

Sorry,

The hammer pushes the correct pin, the wable solenoid charges for a split second causing the wable plate switch to make contact for that split second, the current limiting lamp flashes and it all goes dead. The 1st and 2nd digit light go off and i can start the whole process all over again. It all happens pretty instantaneous.

Ah, ha--now were getting somewhere--
Look at the service manual --look up top, of the pin bank, by the small coil and you should see a "U shapped, copper colored (helper) spring"--is it there --is it broken-???-oneway or another, it's not doing it's job of "assisting" the wobble plate to move when that coil is energized on the first record selected--or that small coil is bad--Ron Rich

Pictures above depict what the switch looks like. I think I have figured out the copper plate is not supposed to be permanently in that position, is it? Essentially, it is always pressing on the switch. I tried pulling the lever back, but it is pretty stuck on there. On a side note, the read out arm is stuck in position, as is the carousel, and the gripper arm. All VERY stuck. Could this all be related to the lever being stuck?

I also checked for continuity in the switch where the two leads are connected, and it is always on.

As always, thank you.

The purpose of that coil is to pull the "Wobble Plate", "out of the way" when the FIRST selection is made--(Once that's made, the selected pin will hold the wobble plate in that "selected state")
With the power OFF, observe that all pins are in the non-seected state, then move any pin by hand--this should be "hard" to do. Set that pin back to the un-selected state , and pull and HOLD the coil plunger in by hand--it should now be much easier to set a pin into the selected state. If the wobble plate is not moving --that's your problem--and I think the switch should be open with no pins pulled, as it supplies power for the read out function-- Ron Rich

The purpose of that coil is to pull the "Wobble Plate", "out of the way" when the FIRST selection is made--(Once that's made, the selected pin will hold the wobble plate in that "selected state")
With the power OFF, observe that all pins are in the non-seected state, then move any pin by hand--this should be "hard" to do. Set that pin back to the un-selected state , and pull and HOLD the coil plunger in by hand--it should now be much easier to set a pin into the selected state. If the wobble plate is not moving --that's your problem--and I think the switch should be open with no pins pulled, as it supplies power for the read out function-- Ron Rich

I think the wabble switch is bad.

I made sure all pins were off and the lever finally released, but there is still continuity between the brown and black cable. The whole thing has basically been in full play mode for who knows how long. The play control relay may be bad as a result?

I'm going to remove and replace. Can I replace it with a radio shack switch that can be manipulated by the lever?

And shouldn't the whole thing theoretically have been moving constantly?

Thanks!

Scratch that. Switch removed and it works great once tested on its own.

The brown and black cable show continuity! How can this be? I even tested from the circular switch to the black cable connecting to the wabble switch and they are connected somewhere. Any idea of what is happening?

Thanks

Look at the schematic--the wobble plate switch and the RO slip ring, are probably wired inn parallel-should read open if mechanism s "homed"-if I remember right---
Ron Rich