Rockola 433 multiple issues

[oldrockandroller]

Thanks I’ll look for that info. I used a regular multi-volt meter, same as I use in my job as a plumber (retired) to check circuits on heating systems etc. Is there better way to do it?

[oldrockandroller]

Ok Ron. In looking thru that info I see that you do not recommend any kind of “sandpaper” to clean contacts. Would 400-600 grit wet/dry paper paper be ok? Unlike regular sandpaper there is no “sand” on it to come off & mess anything up. I have successfully used it to clean contacts on other devices.

[Ron Rich]

I dono--never used it-never seen it, as far as I know ? Most of the info on contacts comes from the companies that make them--Ron Rich

[jukenorman]

You wouldn't (and shouldn't?) use wet/dry paper on contacts that have any plating (gold, silver etc) but it would probably be OK for contacts that require light burnishing. Always best to stick to stick to the tried and tested recommendations though!

With regard to the write-in relay, the button bank switches the ground side (the number and letter latch switches in series) shown on the schematic already referred to. On the same schem-a-gram, you will see that the write-in relay then operates the write-in motor. LOL, I don't know how many times I need to say that manually operating the stop relay will inevitably give the wrong selection; this is simply because the write -in motor hasn't operated to drive the write-in arm to the correct selection.

Norman.

[oldrockandroller]

Thanks Norman. That gives me a clue. Somewhere along the path there must be a bad contact which would explain why the write-in motor is not kicking in. And I do get what you’re saying- the gripper arm is grabbing a previously selected record because it does not detect the selection punched in. As for the wet/dry paper, it’s pretty darn fine at 600. I’ve used it for dirty contacts it all sorts of electrical applications. Heating components, you name it. Sometimes I “lube”it with a shot of non-residue electronic contact cleaner while doing it. I can’t imagine the contacts on a jukebox are that delicate. How would I be able to tell if they are gold or silver plated?

[jukenorman]

Typically, contacts that are passing quite small currents are the ones that are plated. In these cases, the dirtiness is just surface contamination that is best not dealt with by anything even mildly abrasive because the plating is only microns thick. Certain parts of jukeboxes are probably more delicate than you might imagine! As a matter of interest, I've just finished refurbishing a Rock-Ola a few years older than yours; I cleaned every contact and can honestly say that I didn't use anything abrasive on any of them!

Norman.

[jukenorman]

Have a look at the new 429 post from fumosanto with the embedded video - that's what yours should be doing, the stop relay should operate at the point where the write-in arm stops!

Norman.

[Ron Rich]

Hi Norman,
Iffin my great but not too long memory serves me-- ain't that the point the "ballast lamp" should light ( thinkin' it's in series with the relay coil)-or is that lamp powered by one of the relay contacts ?? Ron Rich

[oldrockandroller]

Thanks for the heads up Norman. I’ll check that out. Maybe what I should do is remove the entire assembly where the ADR, write-in & stop relays are mounted to get a better look at the contacts. They are toward the back of the machine & facing away so it’s hard to get a close look. It doesn’t look as tho it would be any easier from the back. Also, I saw a write-in relay for a 433 on eBay for $20 & I am considering sending for it so I’ll have it in the event mine is bad. Of course there’s no guarantee it’s in good working condition. I did get a button/keyboard assy off eBay a while ago & that’s the one that’s in the juke now. It seems in better shape than the original one. The L thru V bank of selector buttons were not working on that one.

[Ron Rich]

Yes-- always better to be able to "see" what you are attempting to fix ! Is that relay a "plug in" type ? If "someone" ain't "fixxed on it a'fore", it's probably fixable--see the contact info in our FAC's section ! Ron Rich

[jukenorman]

These parts aren't particularly difficult to check out and they aren't rare. It would be preferable to carry out logical fault finding I would suggest rather than buying up parts on the off chance.

Here's a practical suggestion for you - with power off, lock the latch relay in the energised position using a wedge of paper, depress a number and letter and then trace the ground through the latch switches to the write-in relay using a test lamp (following the schem-a-gram). These are the type of tests you need to do to make progress.

Ron, the ballast lamp is powered via the stop relay and that part works on this machine.

Norman.

[Ron Rich]

Hi Norman,
Thanks-- my great but not too long memory also is guilty of lying to me Ron Rich

[oldrockandroller]

Hi guys. So now the selector buttons do not even stay depressed when a selection is made. No response at all when pushed. Nothing clicks, no action if any kind. Not sure what May have caused this to happen. Where should I look for the problem? Possibly a contact in the keyboard assy? Seems like no power is there at all now.

[Ron Rich]

Are there any credits established ?? Ron Rich

[oldrockandroller]

No. I checked the transformer in the keyboard assy again & there is no output there. When checked previouslya few days ago, there was 25 volts. So for some reason, as I suspected, no power is getting to the keyboard assy.