Help with Technics Sl-23 TT

Discussion in 'Turntables' started by Daniel N, Mar 2, 2018.

  1. Daniel N

    Daniel N New Member

    Messages:
    5
    I got an old Technics SL-23 as a gift from a relative. It seemed fine albeit turning noticeably slow. However, in my first day of use the pitch issues got worse, until it completely stopped working entirely. The strobe scope lights up, but the motor won't work at all. I know it's not related to the rubber belt, because the motor won't turn even if I take the platter off. I've changed all of the electrolytic capacitors, checked both fuses, cleaned the potentiometers with rubbing alcohol, applied oil to the motor, but nothing worked so far. Is there anything else that I can try? When I turn it on, the shaft of the motor turns just slightly, in a way that could drive you insane just thinking if it happened or not. Please, come forward if you know something that can help. Keep in mind that I'm Brazilian so there ir no deoxit and it is impossible to find a replacement motor here. I know a thing or two about electronics and know how to solder, but I'm new in this audio thing.
     

     

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  2. TomInTacoma

    TomInTacoma d/b/a Vinyl Reclamation Sponsor

    Messages:
    809
    Location:
    DuPont, WA
    The motors on the SL-23 are notorious for getting gummed up and, eventually, stop running. I've had some luck opening up the motor housing and cleaning things up inside. Put a very light touch of oil where the bottom spindle spins. Carefully put the motor back together and you should be in business. It's not a difficult job and doesn't require anything special to accomplish.

    Good luck - and welcome to AK!
     
  3. welcomdmat

    welcomdmat Super Member

    Messages:
    1,055
    Location:
    Pittsboro, NC
    I found my SL-23 to be pretty worry free. I did have to work on the semi-auto function, but the motor was consistent in its function.

    It is a great turntable, so I hope you find some luck.
     
  4. Montycat

    Montycat AK Subscriber Subscriber

    Messages:
    16,845
    Location:
    Vancouver
    Tom is correct. That and similar Technics models often have the motor seize.

    Touch the pulley while the motor is supposed to be turning. You will probably feel a bit of vibration. Apply some oil at the shaft below that pulley and lift and turn it by hand. You quite likely will find that as the oil works in that it will start to spin on it's own.
     
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  5. 6DZ7

    6DZ7 Super Member

    Messages:
    2,042
    Clean the 33/45 speed selector switch (most likely the problem) and the switch under the tonearm that turns the platter on.
     
  6. bberkom

    bberkom AK Subscriber Subscriber

    Messages:
    1,321
    Location:
    Nashville, TN
    This. I have had a couple of these, and the pots/switches usually need a good cleaning to get rid of speed issues. Probably couldn't hurt to lubricate the motor, but your problem sounds like dirty controls.
     

     

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  7. Montycat

    Montycat AK Subscriber Subscriber

    Messages:
    16,845
    Location:
    Vancouver
    While it's a good idea to do that if he is in there, it's really not likely the problem. I've seen exactly what he described numerous times and lubrication, or lack of, was always the issue.
     
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  8. 6DZ7

    6DZ7 Super Member

    Messages:
    2,042
    Just did one with his exact description and it was dirty, waxy lube on the switch. The motor would bump over and stop. It wasn't the motor needing any lube.
     
  9. Daniel N

    Daniel N New Member

    Messages:
    5
    I tried opening the motor, but the thing is, I made a grave mistake, there were some metal tabs that keep the motor spinning in place and I lifted them up, but now that piece is loose inside the motor and I can't put it back together. I am feeling really dumb right now.
     
  10. stereofisher

    stereofisher For the Love of the Music Subscriber

    Messages:
    4,075
    Location:
    Southeast NY
    Fixed one of these for my friend at the local record store. The Sl23 was in good shape cosmetically. It's motor was shot. Unfortunitly, the motors are kind of weak. Sorry you broke the motor. I was able to find a junker on EBay for $25. Took a chance that the motor was good. It was. The store used it as their listening table for awhile. Then they sold it. Though I am not a huge fan, these tables work fairly well.
     
  11. rotco

    rotco Member

    Messages:
    76
    HI Everyone, and @Daniel N

    I just bought one now in not working condition.
    it has exactly the same issue you had.

    motor start spinning for "blink eye" time and immediately stops.
    did you solve it finally?
    what can i do?

    i don't believe it's related to Deoxit the Varistors etc.
    cause i think that will help to maintain a stable turning speed, but not this case of not spinning at all.

    i tried to help the spindle with my fingers, nothing, it acts like dead.
     

     

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  12. illini

    illini The Past is Alive

    Messages:
    6,135
    I was able to rescue a Technics SL-23 belt dc drive motor by applying thin oil (paper shredder oil or Wahl clipper oil) between the motor shaft and the motor bearing. Let the motor run all night and reapply the oil. Unorthodox, but it worked. It was the only solution to the speed drop issue after recapping and relubing the spindle, deoxit, etc.
     
  13. rotco

    rotco Member

    Messages:
    76
    is this motor has a carbon brushes?
    maybe they are wear?
     
  14. Montycat

    Montycat AK Subscriber Subscriber

    Messages:
    16,845
    Location:
    Vancouver
    Yes there might be wear inside but these motors are not designed to be taken apart so, as Daniel found out, it's probably not a good idea to take them apart.
     
  15. rotco

    rotco Member

    Messages:
    76
    @TomInTacoma says its a simple task.
    What did you mean tomin?
    Can i open the motor housing, and by cleaning something brong it back to life?
     
  16. Hamish119

    Hamish119 Member

    Messages:
    79
    Location:
    London, UK
    It doesn't appear to be simple, but here's a tutorial! :yikes:

    Good Luck!
     

     

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  17. rotco

    rotco Member

    Messages:
    76
    Hi all
    some good news!
    I let the motor 12Vdc directly from external battery, and it works just fine.
    First, i wanna say, before i actually did it (what i had to the first of course), i search google for other information and found in few forums few topics about the same exact issue!
    i want to say, that i believe that most of the time, the motors themselves are not the issue since they are really build well and has a great reliability.
    don't go disassemble them and risk vitiate them.

    Now, i need your help to know how to proceed.
    I will say the facts i know:
    1.the motor start spin for a mili second and stops.
    2. the inlet 12vdc to the board exists. (i measured 12vdc at points 1-2 on the pic attached).
    3. the 12vdc isn't exists on the motor +/- points (points 3-4 on the attached pic).

    what are the next tests i can make in order to know which component is the faulty?
    i know there is a diode in the circuit, 6 electrolytic capacitors, and one IC (with 8 legs).

    Lastly, i will say, i deoxit all the turning contacts. (vr33,vr45,switch on, and 33/45 pitch knobs). i used an oily cleaner, so i left it a night to dry and will turn it ON tomorrow. although i will be really surprised if it will fix the problem.

    Screenshot_2018-06-04-23-43-03.png 20180604_234521.jpg
     
  18. Daniel N

    Daniel N New Member

    Messages:
    5
    Hello there.
    I think you should replace the electrolytic capacitors on the board(same value, same or bigger voltage), since they tend to go bad. I did that when I was trying to fix mine, and it made it rotate just a little bit longer each time I turned it on. Then I thought it was a good idea to just disassemble the motor and lubricate it thoroughly, however, that was a big mistake that I deeply regret. Now I'm using another turntable(not as good though). I can't tell you for sure if that it will work out, since it broke the damn thing before it could work. Sorry for taking so long to reply, calculus is literally driving me nuts.
     
  19. Bobsblkwax

    Bobsblkwax AK Subscriber Subscriber

    Messages:
    55
    Location:
    Nor Cal
    I just got a SL23A yesterday. It runs fine on 33, but slow on 45. Could that be the 45 pitch control that needs to be cleaned?
     
  20. rotco

    rotco Member

    Messages:
    76
    I highly recommend not to disassemble the motor.
    the first thing to do is let 12Vdc directly to the motor to see if it's work properly.
    then, for my lucky, it was just a pitch knobs contacts issue. still seems crazy to me that that's what solve the issue, but after i clean them, the motor start work perfectly!
    @Bobsblkwax so, first thing to do is deoxit the 5 components (2 pitch potentiates, 2 varistors, and one switch)


    Please, i need your help in the last issue with my SL-23.
    the pitch knobs (plastics caps) are not sitting correctly for some reason. they are raise from the surface.
    i need a photo for reference, if you could take some for me.
    my main suspect is that the potentiometers are not the original, and that their shaft is higher.
    i cant believe that the bracket they are installed on is damaged or something.
    attached my pics. (hope to see yours for reference)
    thanks
     

    Attached Files:

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