Mech Clutch, trick to lining it up?

Still working on my USC1 but figured the other thread was getting too long and I'll try to keep this one concise. So far in a nutshell: the mech was moving sluggishly (had to wiggle it to get it to engage) when either entering a selection or using the mech start switch. It would not pick up any selection made, however I could manually flip the detent lever and it would pick up the record and play it... a bit slower than it should. I decided to get the mech right first, so I took the clutch off and cleaned it thoroughly, lubed it properly. I then cleaned all contacts around the mech and gapped them properly. I put the mech back together (it looks a lot nicer now) and fired it up. The mech now glides beautifully across the unit..very quiet and it starts up without prodding/wiggling with either a selection or the mech start switch. So now I'm excited, I try to manually detent a record and it properly grabs, clamps and the tone arm plants onto the record then immediately rejects the record. Reading Ron's manual, it looks as though I may have a bind in the clutch (wouldn't surprise me as I did take it apart to clean it). The question is, is this most likely my issue and if so, is there an easy way to figure out if the clutch is properly aligned when reinstalling it? I thought everything was moving fine and I manually tested it a few times with the power off to make sure it would go through the cycle while manually turning the motor (which it did).

Also, will a tormat, contact block, DCC and DES from a USC2 w0rk ok in a USC1 (I do notice a different model # on the tormats between the 2)

Thanks,

Tom

Hi Tom,
Thanks for buying the book--which one are you reading--the Mech. Guide or the Trouble shooting Guide ?
Sounds to me that you may have "messed up" the gaps in the cam switch--check it this way--un-plug the "mech" plug from the amp, and see if a selection will play. Then plug that plug in, while it's playing (if it plays). If it then trips off, the record reject circuit is shorted. If it still returns the record to the rack without playing, it is mechanical in nature. If neither, then it's the cam switch adjustments.
All of the components are interchangeable between the two models--all are "Microlog" models--however, on the DES, the rear boards may need to be changed. On the TMU, they are the same, except for the fact that the USC-1 model requires a long Tormat wire, and some of the other models have a short one ( you can add a "jumper").
BTW--what are the markings on the two TMU's ? I was not aware any were marked other than "160 TM-7" ( and 160 TM-8 were used in "hideaway units").
Ron Rich

Ron,

I was trouble shooting with your Mech guide (2nd ed, pg 38), but i still can't "select" a record, so it wasn't completely a 100% match to the symptom. However, when I flipped the lever during a scan, it would proceed with the symptom described on page 38. (grab -> clamp -> needle hits record (can hear contact through the amp) -> immediately rejects.

Your test you mentioned tells us what we need to know I think. Disconnected the mech from the amp. Scan the mech and flip the detent lever and it now grabs, clamps and plays the record. During play, if the mech is plugged back in, the record continues to play until the end, it then automatically rejects when it trips the "end of record" switch, replaces the record in the magazine and continues on. If I try to flip the detent lever again, it rejects it as before because I've plugged the mech back into the amp. So it looks like it falls under "If neither, then it's the cam switch adjustments" category. I had gapped them (to what I thought was perfect position) according to the manual, but I will take another look. In any case, it doesn't look like I need to remove the mech again to fix this (YAY!) as it doesn't appear to be mechanical in nature.

As for the USC2 parts, I don't know what's in that juke. A friend of mine has an old beat up one but it may have some better components than mine so I may use it as a donor. The tormat on my USC 1 is as you mention, marked "160 TM-7". I was referring to your chart in the mech guide that lists Model, year, # of sels, Mech, Pinbank, Tormat model, etc... I mistakenly looked at the mech and saw a difference in #, not the Tormat... Looks like all the parts from the USC 2 other than the mech are the identical model #s.

On another note, while the record was playing I noticed it was running slower than it should (I have the +/- dial turned all the way clockwise to the fastest speed). I then noticed that the record slowed down as I pushed in on the autospeed plug at J3107. Is this a possible cause of the slow play? I haven't looked it up yet in the guides but will be shortly. One thing at a time I guess

Thanks for the help again. I'm so hopeful this will be working soon.

-Tom

Tom,
You have not read enough--the mechs, other then some "support issues" are all interchangeable--the wire on the TMU would be a "support issue".
As for switch adjustment--I don't recall which book I wrote this in--but it is my belief that switches need not be "messed with" unless there is a known problem with them--I think that you have the 3M-11 and 3M-12 switches out of "phase"--3M-11 MUST open prior to the 3M-12 closing.
On the autospeed--IF, you are playing a 45 rpm record,the autospeed is not a factor ( had you "read the mech guide", you'd know that !), and moving the control will have no effect on the speed. It appears that the autospeed PLUG has problems, if it's affecting the 45 rpm speed--
Ron Rich

Ron Rich wrote:Tom,
You have not read enough--the mechs, other then some "support issues" are all interchangeable--the wire on the TMU would be a "support issue".
As for switch adjustment--I don't recall which book I wrote this in--but it is my belief that switches need not be "messed with" unless there is a known problem with them--I think that you have the 3M-11 and 3M-12 switches out of "phase"--3M-11 MUST open prior to the 3M-12 closing.
On the autospeed--IF, you are playing a 45 rpm record,the autospeed is not a factor ( had you "read the mech guide", you'd know that !), and moving the control will have no effect on the speed. It appears that the autospeed PLUG has problems, if it's affecting the 45 rpm speed--
Ron Rich

Ron,

First, thank you for explaining the concept of "out of phase" on 3M-11 & 3M-12. It makes sense now why one is gapped smaller than the other. You do mention in your Mechanism Guide that the switches, if adjusted according to factory specs, will not cause any problems, even if dirty. My problem was that the juke was delivered lying down and some of the blades were bent as the mech was leaning against one of the lock bars that had been removed and placed in the bottom of the machine. So on my first pass, I only gapped the switches (not accurately), but then decided to clean and re gap according to spec... Missed 3M-12 by a hair. Works fine now.

On the Autospeed, I had to go back and re-read the manuals because I did not recall anything mentioning the speed +/- dial in relation to only affecting 33 1/3 rpm. You mech guide does mention the autospeed (in my USC1) slows down the mech to play a 33 1/3. Tony's guide on Black & Gray Boxes does go into how it works, but only mentions that the +/- changes the frenquency. I should have picked up on that as the output should be set to 44Hz... (45's run at 88Hz) As for the Autospeed plug, I had many female pins that had split, so when I brushed it, it affected playback (one time it stopped it altogether). That has been corrected. The speed issue I was having wasn't a speed issue at all. Luck of the draw, I selected a "test" record, made sure it was flat (no warping) and placed it in the magazine, it seemed to drag a bit. The problem was the record. I'd never seen this but apparently it was stamped (or however they are made) off center. Didn't notice it until I watched the tone arm sway back n forth.

I'm currently at step 3 of phone procedure chart #3 of your microlog jukebox troubleshooting guide as the mech scans twice then stops with no detents along the way- (D cell trick did not make it detent either) need to replace c3104 on 311125-1 as it's a 20uf 35v cap...will be getting one tomorrow. I have also looked at step 4 (detent switch & choke) and have cleaned it and verified the choke value.

I have no questions at this point, but wanted to thank you for your input. I did actually read the manuals (and have re-read them now) and admittedly missed a few things. I'm a proponent of RTFM as well so I apologize if my questions implied that I hadn't. I guess with all the problems with this juke, I'm a bit overwhelmed and just need to take it one step at a time.

Tom

Tom,
You are welcome ! --you'll get it--like you said--one step at a time--- Ron Rich

OK, I've completed phono procedure chart #3, although when I do step 5 (connect analog style meter to dcc test point "read source" and the - lead to ground) I get 124vdc constantly. I suspect my analog meter isn't as analog as I need it to be! I recapped the 311125 board with new caps including c3104. Still does the double scan without detent.

So my sequence looks like this. I can enter the selection on the DES (it will only take a 1 or 2 for the first number, then only up to 7 on the 2nd digit and then any number on the 3rd entry) and it then triggers the mech to start scanning for 2 passes and stops. So it seems that the DES is working. Following the sequence of events from the c3101 (replaced) --> r3103 (removed one leg and tested, resistance is correct) --> L1100 (tested with machine off and mech cable disconnected - continuity properly sounds off as the transfer arm hits the center of each record slot). So I looked at the frog and the Tormat. The frog looks good, no pits and polished contacts. The Tormat's contacts (toroids?) are clean and no pits. But here's something that I find odd. I remember in Ron's mech guide that it mentions the Tormat is pretty much a non serviceable part with the exception of USC1s, USC2s and a few others where diodes could be an issue. I know when diodes go bad, they essentially don't restrict the flow in one direction anymore..they just short. So without opening the Tormat, I figured there should be no continuity on the RCA plug from the center pin to the outside ground ring & wires (a black jacketed and stranded (no jacket) ground cable are soldered to the outside, a green jacketed lead goes directly into the center pin). I tested and there was continuity. I realize it's late here, but that doesn't make sense to me. Should there be continuity from the center pin to ground on the RCA plug coming from the Tormat? (power is off but Tormat is still connected to the Grey Box) If not, is it possible this is caused by shorted diodes?

Thanks,

Tom

Hi Tom,
The DRD to TMU connections are in the write-in loops --that's where the diodes are--
Your problem is the read-out loop--RCA plug, tip to ring, will measure 1.5 to 3.5 ohms, depending on your meter, and temp.
Look at the RCA plug--there should be TWO "wires" soldered to the ring section--shield and a colored one.
If voltage is steady 125 vdc on the read out test screw when mech is scanning, you have an open in that circuit. should read 'zero' with mech stopped, and detent switch closed (service switch/selection pass on "NO" or operate"--if on "yes", reading should be very low-2-4 volts). Should read 55-60vdc with the mech scanning. --Good "ANALOG" type meter readings only--
Check that the 32 gauge wires going to the read out contacts ("fingers") are not both broken, contacts actually are touching rivets----Check detent switch for "pits", broken wires, open choke (3-4 ohms, normal reading), check mechanism cable and plug for broken wire--
Good luck ! Let us know--
Ron Rich

Ron,
Some great progress last night. I would say it's at 90% to 95% functional at this point.

I was finally able to make it to my friends place, he let me raid his USC2... and I did just that! (I really was hoping for a prestine frog, but his has one blade that is bent all the way back and folded over... so mine ended up being in better condition. It still may be an issue, but I'll get back to that.) So, loaded with my new stash of parts, I went home and got to work on your checklist.

1st, my tormat is most likely fine (although I may need to work on a few of the rivets, same as the frog, I'll get back to that). I then decided the newly aquired detent switch looked better than my original, so I swapped it out (I get a 2 ohm reading on that choke, but I get that on both of my detent switches.. I know you said 3-4 ohms is normal). I also reseated the mech plugs at both the jumper box and the DCC. Plugged in the box and what do ya know, it detents... at every spot... but it detents! (unfortunately I did 2 things before testing - detent switch and mech plugs, so I'm not sure which fixed it but I'm betting on detent switch)

Looking at the troubleshooting guide, it seemed to be a grounding issue (as to your comment, there was a shield and single colored wire (black) soldered to the outside ring on each plug, there was a green colored wire to the center pin, so that was good) I crimped the rings of the Tormat RCA plugs to make sure we were getting clean contact and tried again. It again stopped at each spot, but, I noticed that it skipped a few spots at the beginning. Now I had done the D cell trick previously, so my thought was that maybe they were all still active, so I set the selection skip to yes and let it scan both ways till it stopped. Scanned again and it still stopped at each one, but only the ones that were not stopped at previously. So I manually rejected each record, and I'll be damned, it works now! I was under the impression that the selection skip switch would cancel out the previous selections.

A pic of it all lit up..


that's where I left off (was late per usual) so I have some stuff to do this evening to get the other 10% that's left. It has to do with missing a selection occassionally (mech stops but maybe a few selections later, it'll play). I have seen that symptom described in the guide, so I should be good to work on that (hence my possible dirty Tormat rivets and/or Frog issue). The other thing is that it seems to happen only in the upper numbers. I can select anything from the 100s to the 140s (and 200s to 240s) and it will always play first time, first scan. From 150 (250) on, it tends to be hit or miss. I will say that as the mech travels to that end of the magazine, it starts to hum a bit louder as it draws nearer to the end, then it goes away after it reverses and travels away from the end. I'd appreciate any thoughts on that hum.

Ron, thanks for your assistance and patience. Took a long time, but it's going to be worth it to see it in my gameroom.

Tom

Hi om,
No--the "selection pass" switch will not cancel the selections--it just allows the mech to "pass" a selected spot, so the record changer (person) can change records. This is a "carry-over" from the days when the mech was inserted the "other way" into the cabinet. If was finally eliminated in the SPS-2 models.
Choke readings will vary, according to how "good" your meter is--2 ohms is within the range--
Speaking of meters--did you set the "RO voltage" using a meter as per the trouble shooting guide--that's your problem, willing to bet on that, or the bent fingers ! Bent "fingers" on the read out contact block are next to impossible to compensate for--you just gotta change them--That's why you should bolt the mech down for shipment, before moving a phono--
Hum ?? Where is it coming from ?
Ron Rich

Ron,

Checking the RO test point, stationary it is at 120+/-vdc. When scan starts, it hovers between 75 & 80vdc, when it stops and transfers record, it's at 0 vdc, once record starts playing it's at 120+/-vdc again.

When you mentioned the 32gauge wire to the contacts that touch the rivets, were you referring to the contacts on the frog? Speaking of frog, is there a source for replacement contacts/blades for the frog?

As for the hum, I moved the juke into my gameroom and it's not humming anymore. Not sure what it was

Thanks,

Tom