NSM City II carriage does not move to the left

[jonassandstedt]

Hello, I have had this jukebox since the late 90's and have recently removed the bass speakers and have had them relined at a local firm while making rust removal/re-painting of the speakers and the speaker grilles myself. When removing the speakers, I was astonished to notice that there are 12 T10 lamps, accessible from inside the lid, that illuminate the front sign between the bass speakers and illuminate the bass speakers themselves. These have never worked during all the years I have owned the jukebox, and I replaced them with 6 led lamps (see result in picture). At this stage I took the opportunity to replace all electrolytic capacitors on the amplifier PCB. When I started the jukebox again, the carriage only moved to the right, but I was able to get the carriage to move normally by manually moving the toggle switch that is actuated at the left and right end points.



The next problem was the arm that lifts the records, it was contacting the rack that holds the record when the carriage moved such that the arm was bent. The arm’s movement is controlled by a wheel that contacts a cam at the cam shaft; the wheel was worn and had to be replaced. Getting into the carriage was a cumbersome procedure, not being made for easy disassembly (at least in my opinion), but now a new wheel has been fitted and the record lift arm moves as it should.



Now to the present problem, when I started the jukebox again, the carriage only moves to the right to the end position, where the engine buzzes. The switches have hit as they should, and if I lift out the carriage without touching the switches, the cart moves to the right, but slowly. If I then move the toggle switch to the right manually, the carriage quickly moves to the right again. But it never moves to the left, when the toggle switch is set to move left it still moves right, just slower. It is the same result if I select a disc or press the scan button. The toggle switch is easily moved.

If I make a selection or press the scan button, the carriage tries to move to the right (at reduced speed I assume). The carriage is an Ortofon model with a DC drive motor ANM. I notice that the record turntable AC motor SPM changes directions when I move the switch, but not the DC drive motor ANM. I have looked at the circuit diagram, but cannot understand what makes the DC motor ANM change rotation direction? The drive motor ANM has two input leads, but there are three leads in the circuit diagram – is the motor housing acting as a lead? I have re-soldered the connector pins on the carriage PCB, without result.



I am happy for any tips regarding how to proceed.



Best regards

Jonas

[jukenorman]

Hi Jonas,
I think I would remove the the motor ANM (three screws) to determine whether the problem is mechanical or electrical (my suspicion would be mechanical). With the motor out, it will run when you push the scan switch. The motor should change dirction when you operate the reversing switch DS.

Norman.

[jonassandstedt]

Hi Norman,
Thanks for your reply.
The motor ANM does not change direction when I operate the switch DS, but it slows down when it runs in the "wrong" direction. The motor SPM works as is should and changes direction when I operate the switch DS.
Best regards
Jonas

[jukenorman]

Hi Jonas,
Unfortunately I do not have the schematic for the City II (Ortofon). I have a mish mash of NSM documentation and on the original ESII schenatic that I have, ANM is an AC motor. I had a quick look at a Satellite (ESIII) schematic and it shows circuits for both AC and DC ANM motors although I don't know whether that DC circuit would be the same as your's? Do you have a motor relay MO? If so you could check it - but that is very much a shot in the dark! It's at times like these that I discover why I don't particularly like NSM!

Norman.

[jonassandstedt]

Hi Norman,
In my schematics obtained from radiomuseum.org, ANM is marked as an AC motor, but I think that the only difference is that the link at 208 between pin 1 and 3 is removed. When I look at the schematics, is seems as if the motor relay mo1, mo2 only is used for energizing the motor, and is not involved in the motor direction. This jukebox has been very reliable during the 25 years that I have owned it, but I think it is cumbersome to service, even the bass speakers were difficult to remove – a lot of screws had to be unscrewed.
Best regards Jonas

[jukenorman]

Hi Jonas
I'm not being cheeky, but if your schematic shows an AC motor - how do you know that you have a DC motor? Is it from markings on the motor itself?

Reversing an AC motor is quite different to reversing a DC motor so your circuit will not be as simple as you suggest! In the ESIII Satellite, the circuits are totally different; the AC version having a motor relay but not the DC version which is all solid state switching. The reason that I was asking whether your jukebox had a motor relay is because I have worked on Ortofon City II in the past and I recalled there being one. Certainly in the AC version of ANM, the motor relay has no part in reversing the motor; I think its only function is dynamic braking.

Norman.

[jonassandstedt]

Hi Norman
t is a good question. I think it is a DC motor for three reasons - there is a "+" mark on one of the motor terminals, most Ortofon carriages seem to have a DC motor (I am not really sure about this), and the link or bridge at 208 between pin 1 and 3 has been removed - the schematics says it has to be removed in case of a DC motor.
I agree with you that the schematics are confusing, only the bridge at 208 between pin 1 and 3 being the only difference between an AC motor and a DC motor.

Best regards Jonas

[jukenorman]

Hi Jonas,
OK, that seems fair - maybe it is a DC motor! In order to assist you further, I would really need to see that part of the schematic.

Norman.

[jonassandstedt]

Hi Norman,

The schematics are available at

www.radiomuseum.org/r/nsm_loewen_city_ii.html#forum

Best regards
Jonas

[jukenorman]

Hi Jonas,
I can only download three pages (the pages are sections of the overall schematic) per day for free. I have downloaded the section showing the link. That link in in the AC circuits for an AC motor. Somewhere there must be a schematic for the DC motor but looking at the thumbnails that are available at the link you provided, I cannot see anything that looks like a circuit for a DC motor. When I run into issues like you have, I turn to jukebox-world.de where reprints of the original large NSM schematics are available by providing the model and serial number.

Norman.

[jonassandstedt]

Thanks Norman,
I have downloaded all pages and patched them together to four large schematics (I joined Radiomuseum to be able to download all directly). You are correct, there is something strange about this. The schematics are called NSM City II-O that indicates Ortofon as I have. On the schematic called 208 550 B, Electrical scheme, that seems to be an overview schematic, ANM is shown as an AC motor, and the link at 208 that should be removed for a DC motor. One other schematic 218 517 shows the carriage electronics, and here ANM is shown as a DC motor. But here, the motor ANM does only seem to be mainly wired within the carriage, not outside at the other PCB as shown in the other schematic. Perhaps I should contact Stamann at jukebox-world.de and ask about their schematics.
Best regards
Jonas

[Hildegard]

Dear Jonas and Norman,

I followed up this thread.

In 1986 NSM went to a DC motor and there is an extra schematic for the carriage with parts list listing changes and the circuit plate transfer arm.

I uploaded it here: www.jukebox-world.de/Forum/Archiv/Schematics/ESII-O-Laufwerk-DC-1986.pdf

Hopefully it helps to solve the "mysteries".

Merry Christmas to all of you.

Hildegard

[jukenorman]

Hi Hildegard,
Yes that solves it all, thank you very much. It's strange how you can do repairs and when circuits are operational, you never worry too much about how they function. So I have also learned something!

Jonas, that circuit is very similar to what is used in the ESIII Satellite that I previously mentioned. There is also an explanation of how the circuit functions in the documentation. To complicate matters slightly, the schematic is not quite the same as the City II! I think possibly your best course of action is to get yourself the City II-O manual, It's never a bad idea in any case to have the manual. Jukebox World is closed at the beginning of January I noticed so you may have to move fast if you were getting it from there!

Thanks again Hildegard for taking the trouble to upload the diagram. A Happy Christmas to you and to all who use the forum.


Norman.

[jonassandstedt]

Thanks you so much, I did not have this schematic. Yes, buying a complete schematic might be a good choice.
I will look into this during the holidays and will come back if I find something.
Merry Christmas!
Jonas

[Hildegard]

Hi Norman and Jonas,

I am glad that the schematic is helpful.

And how nice that I (= non technical experienced person) was involved that you, Norman, learned something.

Take care you all - Hildegard