" MOTOR NOISE--"/ Motor info--

[Ron Rich]

Oct 21, 2020 16:47:21 GMT Ron Rich said:

Hi All,

Sounds that people interpret as "motor noise" can come from various sources, including the motor-- so let's start by assuring that the noise is motor related ! The simplest way I can think of to do this, is to use the service switch, to shut off the motor ! No noise now ?-- Motor related problem-- still gotz noise-- something else is causing it. 

First place to look either way, is the mechanism suspension-- are all (3, or) 4 of the 9/16 nuts, run all the way up the bolts till they jam ( Tops of bolts were "priened" {sp ?} to prevent nut from slipping down, and off) at the top of the bolts ?  Are the springs holding the whole mech. suspended, or have they collapsed down and allowing the base to "touch something"  ?*  On  all 160 selection mechs., starting with the PFEA models thru the LS-3 an "adjustable, snubber bracket" was installed-- is it still good/there ?  Starting with the USC-1, they used an adjustable "snubber", plus, two "base reflex screws" -- Is that all, adjusted correctly-- are the screws still installed ?  This system lasted thru the SPS-2, at least--can't recall, check your parts catalog. The last system "hung" the whole mech on a "cradle"-- great idea, except the STD-3 and the early production STD-4's eliminated the rubber "cones" that were formerly used- bad idea-- they reverted to installing the cones again.

*The spring collapse, is, IMHO, due to improperly transporting the phono, with the 3 or 4, 9/6 nuts run all the way down (and maybe left there for years ?). Those nuts should NEVER be tightened all the way down- 1/4 inch shims of either wood or cardboard, should be installed prior running the mech nuts down, and the shims removed,with the nuts run back up, when the move is over. (BTW-- don't tighten these down unless you also secure the mech carriage to the base- properly, for your model--see the I & O manual for your model !)

Next-- needle pressure adjustment correct ? If you have a model R, or later model, and  iffin no "repair genius", has touched this adjustment from the day the phono left the factory, it IS STILL correct ! Needle type-- If an aftermarket type it MAY, or may not, pick up motor noise ! Tone arm pivot adjustment been "re-adjusted" ? Once again-- "ADJUSTMENTS" do not change, and need not be re-adjusted, unless assembly has been dis-assembled, and parts replaced !  Properly, OIL, the pivots !

Assuming the suspension is OK, next look at the amplifier. Is the speaker system set-up correctly ?  A system that was set for external speakers, which now do not exist, MUST BE, re-set up as shown in the I & O, or Service Manual.  Next, consider the cartridge/needle set-up. Is the correct Seeburg cart installed, with the spring pressure set correctly (No, despite the miss-info you may see elsewhere, the "mono Black head, Red head, and Pickering model 345 carts.", are NOT, directly interchangeable-- see the needle info sticky--also "color"of the needle housing DOES mean something-- they are NOT all "interchangeable" -- see the sticky !!)? 

Next, is the phono "set for free play", or are credits established-- latch bar solenoid "humming") ? NOTE, on the LPC models a "hum shield" MUST still be (!) installed over the solenoid !  Is a florescent lamp ballast "humming" ?

OK-- On the motor. OIL-- is the whole drive train, including the motor properly oiled--using the proper oil ?? Starting on the bottom, of the motor, is there a semi-pliable, motor support installed ( these, even when new are not too "spongy") ? Are the two rubber motor supports still OK ?  Is the motor coupling pliable, and, CORRECTLY, installed (see my "Seeburg Mechanism Guide") ?  Are the two turntable (TT) grommets OK, and is the TT itself "floating" on the two internal ball bearings ?  Hint, if the TT is not floating , most of the time you can "un-stuckit", in the following manor : With the mechanism in play/power off, take your hand and "hit" the TT, shocking it, in one direction. Then do the same in the other direction. If "un-stucked", as it should be, you will be able to put pressure on it in one direction, and it will "spring back", due to the grommets, when you let go.

 

MOTOR INFO--- All brand 4 wire motors, are interchangeable, with each other, in all models from the model A on up thru the STD-4 & 100-78D models. All wire colors are the same--( the 4 wire Bodine KCI-42, was first used--far as I know -- in the 'Shoot the Bear" type games, pre WW2 !) Starting with the SMC-1, a 3 wire NIDEC motor (--0413), or a 3 wire Bodine (KCI-42 A-1B) was used--wire colors are not the same --NIDEC colors shown on schematic to Bodine colors here-- blue to black-- white to blue--red to green.  Motor run caps are not the same either, ALL, SMC types, use a 2.2-2.2 cap !

 HTH, Ron Rich

[armandh]

another 'motor" noise
if the second section of the motor cap is some how connected during play.
bent switch leave etc.

[Ron Rich]

Hi Armand,
Yep, you most certainly are correct---- but that causes more of a "growl" then noise ! LOL, Thanks, Ron Rich

[jukeboxcharlie]

New (Seeburg Electra) jukebox owner here, currently troubleshooting a motor noise problem.

I would describe the motor hum as a mid-range pitch coming through the speakers from the motor.  I know it's the motor (not the amp) because it is the exact same pitch as the sound that the motor makes in the mechanism, and stops coming through the speakers if I lift the arm off the record (ex. while it is playing).  Also, it is louder towards the end of a record (where there is less vinyl to absorb the vibrations coming from the centre), than the beginning.  Between this thread, the official manual, and Ron Rich's excellent book, I am hoping to solve this issue myself.  Here are the steps I have taken so far, with a few questions that I am hoping someone in the group may be able to answer!  ANY feedback - from "I had this problem and here's what I did..." to  "it's in the damn book!" - is much appreciated! 

ITEMS I AM EXPLORING:
1.  The first point Ron makes below is to "First place to look either way, is the mechanism suspension-- are all (3, or) 4 of the 9/16 nuts, run all the way up the bolts till they jam (Tops of bolts were "priened" {sp ?} to prevent nut from slipping down, and off) at the top of the bolts ?".  

*** I found 4 bolts (2 on each end of the "mech platform" (is that the correct term?), and they are run all the way to the top but they do not "jam up" at the top of the bolts, but in fact can be easily removed by hand. Is this normal or does it mean I am looking at the wrong bolts/nuts??
*** Here are 2 of the 4 bolts on my machine - are these the right ones:  ibb.co/zP5r2DG?

2.  The springs holding up the "whole mech" (platform?) seem fine.  It is floating on all 4 corners.

3.  Is the motor coupling pliable?  I think so but it's impossible to know how pliable it "should" be... It feels only "slightly" pliable to me, i.e. more like plastic than like rubber.
*** Can anyone venture to guess whether this is "pliable enough" or whether it should in fact feel more like rubber than like plastic?  And how I can tell if it has been improperly installed?

4. Oiling the entire drive train:  I did the easy parts (ex. added oil to the 2 cups on the motor, added to the felt wicks inside 2 screw heads near the gears, added a bit to all the gears).  Unfortunately, most of the lubrification points seem to require access to the rear of the mechanism, which I assume requires its removal from the box. I am not there yet so I skipped these lube points...

ITEMS I HAVE NOT YET EXPLORED:

5.  What is an "adjustable snubber bracket"?  I know it will be difficult to describe in words, but if anyone can confirm that it appears in one of the diagrams in either the official manual or in RR's book, that would be great.  So far I have not been able to find it.

6.  No idea if the needle pressure adjustment is correct or what needle type I have.  Going to park this one for now and come back to it (with a pressure gauge and new needles if necessary)

7.  Are the motor supports (3 - 2 on either side, 1 beneath) OK?  believe these are rubber pieces that should feel relatively firm...  Have not yet found them, assume I need to remove the mech from the box to properly inspect.

8.  Have not yet checked the TT grommets, but I can see where they are in the official manual (p. 2475 "Turntable, Shaft and Gear Installation").  I will inspect these later if necessary, along with the "motor supports" if I remove the mech...

9.  Is the TT floating on 2 internal ball bearings?  No idea, but there seems to be some springiness in the TT assembly due to what I imagine to be rubbery grommets (8)...  Hard to know how springy it "should" be as I have no frame of reference.

[Ron Rich]

Hi Charlie,
I think I have answered most of this somewhere ?? But--I'll do it again--
1. Bolts were peined (sp ?) at the factory to lock nuts at the top.
2. springs and "snubber bracket", should hold mech base, with carriage parked in the center, level.
3. No guess-- gotta have "hands on" here.
4. Did you use the correct oil ? (See sticky in FAQ's) Rear is accessible by removing rear access panel, on that model !
5. The snubber bracket is visible from the rear of the cabinet-- consists on that model of two plates glued to a yellow colored foam rubber--adjusts by moving a plate fastened with about 4 screws should hold the mechanism firmly in place. It is really not necessary on that model as the new style cartridge introduction got postponed to the next model.
6. Did you read the stickies on Seeburg needles ?
7. Do not "ASSume"-- motor can be seen from front inspection "hole" easily with the mech cover removed.
8.&9. sounds as if they are both OK.
Ron Rich

[armandh]

more like plastic than rubber is likely hard

one thing we did was to put a Teflon strip at the end of the TT shaft
loosen the two screws holding the end play adjusting bracket and slid it in, re adjust.
I do not know which side of the steel ball it went on.
[that ball should normally be found between the end play adjusting screw and TT shaft]

[Ron Rich]

Hi Armand,
The ball bearing (should) sit halfway inside the hollowed out, end of the shaft. There were two design changes done in that area-- first was to replace the spring steel cover with an adjustable set screw (and a holder for the screw). 2nd. The set screw was case hardened. What I have seen happening over the last 30 + years, is either the screw has deteriorated or the ball bearing has deteriorated, due to lack of proper (graphite grease/oil) lubrication . I almost always at least change that (.187) ball bearing, and if hollowed, either grind, or replace the screw.
BTW-- this usually when bad, causes motor noise only in one direction ! Ron Rich

[jukeboxcharlie]

Pleased to report I fixed the motor hum issue.
Turned out to be all the rubber parts - items 3, 7 and 8 above - all rubber was getting brittle and stiff. In fact the ribber grommet that the motor should sit on - was not even present.
Sounds great. Which is nice.

[autopro100]

Hello all, and thank you in advance. I have a SMC1 1978
Disco that seems to play fine on the B side but when playing the A side the motor shutters, gets hot, slows down and shuts off. I know little about the machine as I just picked it up.

[Ron Rich]

That's a totally different can o worms-- Which motor is in the phono ? The IFB is probably failing--- Ron Rich

[autopro100]

Hi Ron, it’s the Nidec 3 wire but I swapped in a advertised good motor, good mounts and the problem seems the same, so I missed that one anyway the sound is good, lights are good and the records load after about a week of cleaning and fix up. Assuming both motors don’t have the same problem?

[Ron Rich]

Quite obviously (to me)-- It ain't a motor problem--my guess woodbe, as stated above-- an IFB failing. DIDJA PROPERLY oil the motors--NIDEC's are famous, for "locking up" and burning out, if not properly oiled ! Ron Rich

[autopro100]

My apologies Ron I misunderstood your post, and yes that sounds right, so how do I fix it?

[autopro100]

Oh, yes I oiled the motors they spin well and between the two of them I found two good mounts.

[Ron Rich]

Well, you get out your trusty copy of the service info for the SMC's-- look at the schematic for the IFB (BTW-- which "Rev" (version) is in that phono ?) and you trouble shoot that 311780, IFB. Now check the motor you are using-- do you have oil in both cups ? If not-re-fill them !
Do you have the skills needed to trouble shoot "C-MOS" ? If not, email me at: [e-mail] Ron Rich