Rockola 470 read out arm misses some pins but not others

[biyf]

Hello to the group! Been reading many of the older threads here and of course the stickies, but haven't found anything that matches my exact issue yet.

I've previously fixed two Sybaris 474s, which suffered from various issues - one was simply a mechanism lubrication and amp recapping, but the second was an absolute basket case with every electronic module except the power supply needing gone through and parts replaced. I do have a manual for the 474. 

Now I'm working on a 470 and have got just about everything working, except that 1) the readout arm doesn't stop (either A or B side) on a series of pins in a row, and 2) some pins (just a few randomly spaced), when engaged, don't provide power to the readout arm and start the search cycle. For issue #2, these pins, though they don't start a search, will be caught by the readout arm after triggering a search with a different pin. For issue #1, I have not yet removed the readout arm as I wanted to double check the inside and outside "Key levers" that look like they are supposed to engage with the pin to stop the readout arm - according to the manual, "the striking of the selector lever by the readout carriage contact completes a circuit to the interlock trip coil," and a pair of contacts transfer. I am thinking the key levers aren't actually supposed to engage with the pin but really not sure. 

Thank you in advance for any advise you can offer!
David

[Ron Rich]

Hi David,
?? "-some pins don't provide enough power---"- ZERO "pins" supply any "power" ?? Search is "started" by the MicroSwitch on the wobble plate ! Is the "U shaped" copper spring up there any good ?
If the read-out arm fails to stop on --fully-- selected pins, but does consistently, on others, I would assume the contact ring is "dirty"-- see the above sticky on 400 problems-- Ron Rich

[biyf]

It seems another cleaning of the contact rings resolved issue #2. Sorry, didn't mean the pins supply power; they just don't trigger the wobble plate switch to kick in and start the search. Either way that one seems to be resolved. The U shaped copper spring on the wobble plate switch looks good and seems to be doing its job of engaging with the micro switch. 

Still having issue #1. Perhaps there's a lose wire in the molex, will check those.

[Ron Rich]

OK-- you have me comfuzzed-- what'z "issue #1" ? "Molex"-- ain't no Molex brand connectors, that I know of, ever used by RockOla ! Did you use Deoxit -5 as stated in the sticky ? Ron Rich

[biyf]

I am using CRC QD Electronics cleaner. If that's not good I will order the Deoxit 5 and try that instead. Just meant I would double check the wiring connections that snap together, whatever they are called. Sorry if my description is off.

The readout arm is now sometimes stopping on some of the troublesome pins after more cleaning. I am trying to understand what exactly triggers the readout arm to stop on a pin. Is it the plastic "key" or the wipers on the contact rings?

[jukenorman]

If you are using the 474 manual, then you should refer to sequence 14 on pages 46 and 47 of the manual - that will answer your question re the read-out arm stopping.

Norman.

[biyf]

Norman and Ron, appreciate the help very much and your patience with my descriptions! My previous quote above about the readout carriage contact was from page 47 of the manual. I just didn't know if the "contact" mentioned was the leaf on the ring, or the plastic key engaging something I can't see to trigger a pulse. I must assume it refers to the leaf to ring contact - I'm just having trouble wrapping my head around that I guess, since I don't see individual contacts for each record that the leafs engage with on the readout side of the wobble plate.

Also the search motor is randomly tripping the mechanmism circuit breaker, so there must be a weak connection somewhere.

[biyf]

Readout problem is fixed. Thanks for the help! I removed the readout arm (was reluctant to do so but turns out it could not have been easier) and located the A side and B side contacts right away. Cleaned them up, increased the pressure with a slight tweak of the leaf spring, and we're good to go.

Still tripping the mechanism breaker randomly while the search motor runs if anybody can suggest where to look on that one. That's the last thing left on this jukebox (until the next thing pops up!).

[jukenorman]

By the search motor, I presume you mean the magazine motor? In which case, it no doubt requires cleaning and servicing. As Ron never seems to tire of pointing out, it helps if you use the terms in the manual so that we know exactly what you are referring to!

Norman.

[biyf]

Thank you, Norman. I'll give the magazine motor a thorough cleaning and lube and report back if not fixed.