Pioneer SX-850 No relay click

Discussion in 'Pioneer Audio' started by jwallace2011, Feb 28, 2011.

  1. markthefixer

    markthefixer On Hiatus, dealing with Dad's estate full time Subscriber

    Messages:
    20,990
    Location:
    Bensenville,Illinois
    yes, fresh eyes,

    Q4: 512-KSA1013YBU
    e: -23.3v
    c: -13.7v
    b: -14.3v

    makes more sense as:
    Q4: 512-KSA1013YBU
    e: -13.7v *** because of the zener D12
    c: -23.3v
    b: -14.3v

    but -23.3 is still low. use a new q4 if NOT installed correctly. lettering facing you, leads pointing down, q4 is ecb.

    Q2: 512-KSA940
    b: -23.3v
    c: -67.5v
    e: -22.8v

    is doing what it's told (b -23.3v) so (e -22.8v)
     
    Last edited: Jul 19, 2013

     

    Please register to disable this ad.

  2. JohnDoe99

    JohnDoe99 New Member

    Messages:
    26
    deleted
     
    Last edited: Mar 2, 2014
  3. JohnDoe99

    JohnDoe99 New Member

    Messages:
    26
    deleted
     
    Last edited: Mar 2, 2014
  4. markthefixer

    markthefixer On Hiatus, dealing with Dad's estate full time Subscriber

    Messages:
    20,990
    Location:
    Bensenville,Illinois
    Do not reinstall, 6 way diode test them for gross faults first, any time there's more than 5 volts base to emitter the transistor is toast.
     
  5. JohnDoe99

    JohnDoe99 New Member

    Messages:
    26
    deleted
     
    Last edited: Mar 2, 2014
  6. JohnDoe99

    JohnDoe99 New Member

    Messages:
    26
    deleted
     
    Last edited: Mar 2, 2014

     

    Please register to disable this ad.

  7. markthefixer

    markthefixer On Hiatus, dealing with Dad's estate full time Subscriber

    Messages:
    20,990
    Location:
    Bensenville,Illinois
    clean the pot,

    re q4, q6: go buy a lottery ticket, you are riding on a wave of luck... :D

    in other words, they are behaving, and thus hopefully didn't suffer damage.
     
    Last edited: Jul 20, 2013
  8. JohnDoe99

    JohnDoe99 New Member

    Messages:
    26
    deleted
     
    Last edited: Mar 2, 2014
  9. NavinJohnson

    NavinJohnson Professional Amateur

    Messages:
    679
    Location:
    Raleigh, NC
    happy ending.

    thanks for the perfect schematic of the 850 950 power supply. its in the file for my use at a later date.
     
  10. tsd71

    tsd71 RIP Tom Petty Subscriber

    Messages:
    2,569
    Location:
    New Jersey
    No problem, glad I can help you...nice work!
     
  11. eamonhegerty

    eamonhegerty New Member

    Messages:
    9
    I have a defective SX-850 (no sound/no relay click). I've separately tested the relay and it is working fine (coil energizes and contacts make with low contact resistance). My power supply pcb is a -101 variety rather than the -102 I see in the manual schematic I've downloaded. R5 is 56k, not 150 Ohms. R6 is a 150 Ohm resistor though..is that the resistor referred to as R5 in the thread above? I tested the pin voltages and all are per the manual for the -102 pcb other than pin 11 which is 19 Volts and not 28 Volts as stated on the -102 schematic. Do you think the problem still resided with Q5 (or Q7)?
     

     

    Please register to disable this ad.

  12. Watthour

    Watthour Electron Rancher - JS3600

    Eamon - It is probably best to start a new thread for your particular problem. While it is good to search through the archives for information about similar problems, adding to this thread could likely only become more confusing when diagnosing the specific issues in your unit.
     
  13. eamonhegerty

    eamonhegerty New Member

    Messages:
    9
    Sorry for the long delay in responding. Thanks for the tip!
     
  14. slipstream55

    slipstream55 Active Member

    Messages:
    228
    Location:
    Gilbert, Arizona
    A bit off topic but, my curiosity is piqued regarding this thread. What happened to all of the responses by JohnDoe99? They're all deleted. Thanks.
     
  15. Radiomandan

    Radiomandan New Member

    Messages:
    12
    Location:
    Sedro Woolley, Wa
    This thread just saved my day. Friend dropped off his SX850 for repair as it had the same issue and matched the voltages by the OP exactly. Went right for Q5 and I had voltage on the Base and Collector nothing going out to pins 8,9 and 10 that sends power to the Protection Relay. Followed the Gurus advice and ordered a couple beefier transistors to replace Q5 but since the ones it feeds are unchecked at this time I'll pop in nee ones ass well while the board is lifted.

    Man I am impressed with this beastie. Can't wait to hear it rattle the rafters when it's done. He's plan info on running a set of Advents on it I believe. I'll be resting with my 901s. I'll have to find one of these of it makes my 901s sing.


    Also replacing the 15000uf 50v filter caps and bleed resistors and replacing the indicator lights as a few are out with a few dial lamps. Nice kits from eBay available. Thanks to the Gurus on this thread. I was fearing a total power supply rebuild and may still in the future.


    *Note is the tool Pioneer used to make these awesome wire wraps available? What is it called. I thought they were all soldered I couldn't believe when I see it's just rightly wrapped on the post. *

    -Dan
     
  16. Stoneage1000

    Stoneage1000 New Member

    Messages:
    1
    Hi !
    Thanks for this thread, really saved my day. Changed the Q5, now my 850 plays great.

    /Marcus
     

     

    Please register to disable this ad.

Share This Page