Seeburg SMC1 / Disco flutter sound

Hi,

I posted a video of the sound coming out of the jukebox here
The Amplifier is fine, when hooking up a record player it sound super!
Without amplifier on, you hear the same warped/flutter when you listen to the needle on the record.
Needle are new ones
Mech is cleaned and oiled. It has played a few songs now.

My question is, is this the mech doing funky stuff or is it the cartridge that is busted?

William, the cart won't cause that, this is mechanical. It is called "flutter".

look for:

1) Hardened, poorly locked motor coupling.

2) Motor mounts sagged and allowing the motor to be slightly off-center.

3) Possible vibrations in the top bearing over the motor. This will usually squeal too. remove it and apply lube directly into it (don't lose the ball bearing).

Check that the contacts that apply extra capacitance to the motor during changing/scan are not still closed in play mode.

Rob/NYC

William, Rob,
Did you oil that motor with the proper oil, as I stated earlier--if so, or if not re-oil it, several times--fill the two oil cups, let it "drink", and fill again. Those motors are known for seizing, when run dry--and that's what it sounds like is happening to yours. Also, saturate the fiber gear with the same oil, and be sure the top of the clutch --and rest of the moving clutch parts are oiled.
If that motor has "jammed" at any point in time--the motor coupling will look "twisted", and have become "hard". If this has happened, it must be replaced, properly. Motor supports and motor plug are also suspect. Also check that the two enclosed turntable bearings are not frozen, and that the record is clamped tight, and not hitting "something".
Rob, You are incorrect on the added motor cap contact--On SMC models, it MUST MAKE, not open, in play position !
(Having it "open" on this model would be a "gepetto repair" , since one would need to dis-assemble the point stack, and reverse the contacts that are used for the motor cap).
Ron Rich

William,
Just had another thought--this type problem can be caused by the IFB, in the PPC. Usually, a leaky BDT--or, un-updated PCB. Ron Rich

Thanks for all the replies, great having some help.

Rob >
1) Hardened, poorly locked motor coupling.
The coupling is still flexible and is tightened.
2) Motor mounts sagged and allowing the motor to be slightly off-center.
One motor mount, the top one, was very very bad and I have replaced it.
3) Possible vibrations in the top bearing over the motor. This will usually squeal too. remove it and apply lube directly into it (don't lose the ball bearing).
I looked at that bearing and oiled it. It looks fine and sounds good as well. No weird noises. Perhaps I can
Check that the contacts that apply extra capacitance to the motor during changing/scan are not still closed in play mode.
The contacts are open when in play. When I close them the motor speeds up just a little. Actually, it sounds as if it is better up to speed then.

Ron >
Yes, I oiled that motor multiple times, I will continue to do so some more. All moving parts are oiled. The top motor mount was very very bad, perhaps the motor has been jammed before. The thing is, everything feels very light when I turn the motor by hand. Same goes for the clamp and the turntable. All seems ok. But what I think is OK can be wrong of course.

The other cause you mentioned is in the PCC. The only thing I did not understand was what you mean by "leaky BDT" ? The board is certainly not the best, and someone did do repairs on it before me that did not know how to fix stuff. And that was at the motor controls. I could run the motor with external power of course to see if that is the problem.
Or am I missunderstanding you Ron ?

How about the motor capacitor? Could that be at fault? Because the motor does seem to run a little slow as well.

Things I will do:
Keep oiling motor
Test motor with separate 120V
Find out what a BDT is
Perhaps open up the motor and examine it / clean it

Thanks for the info, and keep your hints coming!

William,
Something you have written has triggered a few questions--
What brand motor is installed -- How many wires and what colors are they, on that motor ?
Which motor run cap., is installed ( values stamped on top of can ) ?
Motor coupler must be installed to take up ALL -up-down "play" in whole shaft--check also the TT thrust bearing adjustment, and the clutch top thrust bearing adjustment--
BDT ??--gonna make you work for that info--RTFTM ! (Hint, use ONLY one, or the other, as specified--no "subs" !)
Ron Rich

Hi Ron, here are some answers

It's a japanese Motor, Nidec SBI-0413, has 3 wires green, blue and yellow. The Cap has 2x 2.2uF 260V.
When looking at the schematic it seems to have been wired correctly.

When I put the motor back after placing the new mounts, the top screws of the coupling were fastened, then I placed the motor back (new motor support plug installed as well) and tightened the bottom screws of the coupling. I can feel no noticeable up/down play on the coupling.

I will check the thrust bearing adjustments of the TurnTable as well. I have removed the TT to install new rubber drive bushings last week.

Yesterday I ran the motor on a separate power supply and the sound is still 100% the same, making me rule out the PCC.
I checked the bearings, cleaned and oiled them with 20 SAE oil. They were not really dirty.

The one thing that strikes me as odd and makes me think of your comments about the motor Jamming, is that the motor tends to feel warm pretty fast. I do not think this should happen this fast. I think I'll open up the motor tonight to see what is going on in there.

BDT, so thats a BiDirectional Thyristor, sorry I did not know that Abbreviation.

MrMario64 wrote:Thanks for all the replies, great having some help.

Check that the contacts that apply extra capacitance to the motor during changing/scan are not still closed in play mode.
The contacts are open when in play. When I close them the motor speeds up just a little. Actually, it sounds as if it is better up to speed then.

As Ron points out in these models the contacts are supposed to be -closed- unlike the older motor systems that I was citing. Take another look at them and see if they are out of adjustment.

Techies (and teachers) love jargon and acronyms -it makes then (us) look smarter. A BDT is simply a Triac. Triacs are often used in logic control circuits in place of standard relays. They are simpler-cheaper to apply in those applications. Turntable motors are often controlled this way.

Rob

Allright, well it's absolutely OPEN on my Mech, so thats not right. Weird, because it looks pretty good to me

In the Schematics (MCC schematics) I see that the contact should be open in play, that contradicts what Ron says.
While I have complete faith in your knowledge Ron, I did want to point this out. Perhaps it depends on the motor or??

So in play, both caps are in circuit and motor runs a little faster.
In scan, only one cap is in circuit and motor runs a little slower.

I will check this this evening to see how I can get it back to original without bending stuff.

ps. I uploaded part of the schematic in this thread but was not sure if it was allowed so I removed it. It was the Mechanism Schematic shown in the Microcomputer Control System.

That schematic clearly shows _open_ in play. That is how I remembered them, but I didn't deal much with the later models. I'd leave that alone and see what Ron says.

Do you have any way of measuring that capacitor? If not you can try subbing non-polarized caps to make up the 2.2 value needed in play mode.

Rob

Hi Guys,
The "Tech. Manual", pages 27 and 41 show that as open in play--this is absolutely WRONG!
The top contacts on the upper stack (1M7 switch- drawn wrong) must be open in SCAN, closed in PLAY, on the SMC mechanisms.
William, I am sure it will sound better, if you adjust that contact to close, in play position. It should close just prior to the needle landing on the record. ( I added this error to the list of errors, above)
Ron Rich

Hi Ron,

I will have to see how I should change that on my jukebox.
When I close the switch manually the motor speeds up a little and sounds closer to 45rpm then, but it does not sound better. Still flutter.

The motor coupling is still intact, but is indeed a little hard. I will buy a new one for that.
Other than that, I really have no idea. I checked everything you said and never is there any change in flutter.

Things I checked:
Oiled and checked bearings
Checked TT Thrust bearing
Cleaned motor
Replaced motor mounts
Motor Run Capacitor measures at 2x 2.7uF

Only things open still are:
Stiff motor coupling

William,
Can you send me a photo of the upper switch assembly on your mechanism ? Send it to: ronnnrich@yahoo.com
Maybe I can see what's happening ?? Ron Rich

Thank you, I sent the picture.

William, Rob,

I must apologize--I don't know where my head was, but the motor cap, add, switch is OPEN in play--closed in scan--same as all other Seeburg 45 rpm mechs ! (cap values are different) Ron Rich