USC-2 clutch problem

[paradisecs]

I got my USC-2 put back together finally.  The clutch was removed and completely cleaned and oiled.  I've gone through all the adjustments in the manual for the clutch and the rest of the mech.  "B" side pulls records, plays, rejects, and moves to the next selection with no issue.  "A" sides pull the record, play, reject, then it sits there and clicks three times while the mech jumps a bit each time before finally moving to the next record.  It doesn't matter what 100 number I pick, it does the same thing and it's always three clicks. 


I'm sure I have something adjusted wrong but I've gone over the clutch adjustments multiple times and I end up exactly back where I started.  I can't seem to figure this out, especially since it's only the "A" sides doing it.  Which adjustment is most likely the culprit?  I've also checked the thrust bearing and that seems correct as well.

Stephen

[Ron Rich]

Stephen,
Do you have a copy of my "Seeburg Mechanism Guide"-- If so, look at the clutch section. The usual cause of problems like this are incorrect adjustment of the top clutch thrust bearing screw--loose "large support block arm" on the yoke, or a frozen clutch yoke pin. Rare--but happens, is a loose swedging (sp?) on the clutch release roller, support. Ron Rich

[paradisecs]

Thanks Ron. I refer to your Guide all the time. I'll check the thrust again. I have a better gap gauge so maybe I'll get lucky. For it to be the yoke pin wouldn't it have to be doing it both directions? It's the one side only that has thrown me.

Stephen

[Ron Rich]

Hi Stephen,
No sir--It will manifest itself on one side or the other (usually when the tone arm is "outside" first), if any one of those are the cause--It will worsen, to the point of doing that on both sides, if not fixed, and will eventually require the clutch member replacement, along with the repair of the original cause ! Ron Rich

[paradisecs]

For clarification where should the detent arm retarding spring be attached to? I'm looking at mine and it seems lose; like one of the ends is in the wrong spot. It may be fine where it is but I can't tell from any of the drawings where it's supposed to be.


I should say, where are the ends attached?  It's mounted in the right spot but I don't think it has enough tension on it and I can see one end moving up and down on the front of the clutch housing.

Stephen

[Ron Rich]

Stephen,
On all but the last few production runs of the mech, that spring was attached to the "nut plate" that held the detent switch to the casting-- the "hole" to attach it to, should stick straight out from the plate--not be bent back ( as I have seen many) towards the plastic actuator. On the last mechs. this plate was eliminated (thanks to me -- I won that war--took forever !) and a hole for the spring was drilled in the casting. It will work fine as long as the detent switch is able to OPEN, as per the manual. Ron Rich

[robnyc]

Stephen, in addition to what Ron mentioned,  in my own experience mech bucking is the direct result of worn scan (bottom) notches in the clutch member.

This affects the A sides more because that is what gets played most thus those notches take the most hits as they attempt to couple the bottom gear.

If you look at the clutch you'll see a rounding and a peened indentation where the lower pin has worn into the clutch member. I had several NOS members so that is what I've used. I also filed worn clutches to restore proper notches: www.flickr.com/photos/90641375@N06/page4 This works just as well.

RobNYC

[paradisecs]

I'm starting to think it is something like that. No matter how many times I redo the clutch and thrust adjustments nothing gets better. B side good, A side stutters. This last round yesterday I'm no longer getting the detent actuator moving back and forth. It's not broken but that is when I noticed the retarding spring seems to have slipped out of it's mount (I can see the arm of it about 1/4in down on the frontside of the clutch frame. I'll pull the clutch and check for worn parts again. I didn't notice any but I have learned a lot since I last inspected it.

Stephen

[Ron Rich]

Stephen,
You can look at the clutch member on that mechanism by un-plugging the DRD, and the Pop meter, then loosening the two machine screws holding the pop meter against the TMU. At which point, you can raise the pop meter (you MAY, need to loosen the top two support screws on that frame also) frame to have a clear shot at seeing the clutch when the mech is on the "100" end. Turn the motor coupler ( be SURE the read out arms are out of the way !! ), to get a better view of the "V" notch, and you can view if the member is bad. I slightly dis-agree with Rob here--"filing", MAY cause the pin on the drive gear too much strain--probably would be OK on the slower drive mechanisms--but the "speed-ed up" versions--I dono ! Ron Rich

[paradisecs]

So in the process of looking at the clutch and readjusting things I seem to have messed up something electronic. I can't make selections any longer.

I press a number and the scan never starts. No errors on the keyboard, it just sits there. I can start the scan from service switch but then no selections are made.

The battery test does work however. Voltages are all good on the DCC. And it was all working before I moved the greybox out of the way to look at the clutch again.

I swapped out the scan board since I had a spare here and that didn't change anything.

1st digit, 2nd digit lights come on normally but no scan after the third. I did notice that if I enter 180-199 or 280-299 I don't get an error. I've never tried that so not sure if that is normal.

I am sure I did something that should be obvious but I missing it, what ever it is.

I'll delve in to the quadrabit testing later this weekend but thought I'd ask if there was something else.

Stephen

[Ron Rich]

Stephen,
Check the connections to the DRD--especially pin #15 on the short plug--and the single ground return plug there.
Ron Rich

[paradisecs]

Okay found my problem. The selection pass was stuck in the yes while the actual switch was on no. Fixed that with potentiometer cleaner but inspection of the greybox connectors led me to another issue. There is a frayed wire on pin 7 (black/brown). How do I remove the pin to fix it? I'll just solder the wire to the pin to strengthen it but I'd rather not do so while in the plastic.

Stephen

[Ron Rich]

Stephen,
First--which brand connector was used on that phono plug --Molex, or A-MP ? 2nd--how much wire is left on that pin--can you remove the pin and slip some "heat shrink" around it--will there be enough strands left to hold ?--If so, that's what I'd do--before attempt0ing to "solder".
Ron Rich

[Ron Rich]

Hi Stephen,
That selection pss switch was not "stuck on yes"- it was failing to make contact on "no"-- a common problem with that type switch !

[paradisecs]

I'm not sure what brand the edge connectors are. How can I tell? If I can get the fingers out of the connector then yes, I can heat shrink it.

Stephen