pioneer sx 1050 powers up but no sound.

Discussion in 'Pioneer Audio' started by kubotadave, Feb 4, 2019.

  1. kubotadave

    kubotadave New Member

    Messages:
    43
    Location:
    watertown ny
    SOFT RELAY CLICKS BUT NO CLICK FROM PROTECTION RELAY awm 90 1=0 2=-12.6 3=7.43ac 4=0 5=0 6=0 7=0 8=0 9=0 10=0 11=0 12=62.9 awm103 1=23.4 2=79 3=-80 4=0 5=13.6 6=13.6 7=-12.7 8=-58 9=-29 10=-24 11=-24 12=0 13=26 14=26 15=32.3 16=63.3 17=63.3 18=5.3 19=5.4
     
    Last edited: Feb 4, 2019

     

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  2. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    Protection pin voltages?
    Some are AC and most are DC.
    Check the schematic for the proper voltages.
     
  3. kubotadave

    kubotadave New Member

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    Location:
    watertown ny
    Just listed them on original thread
     
  4. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    Got it. Will have to wait until tomorrow. Very busy.
    At first glance. Something is not adding up.
    Re-posted for clarity.

    AWM-090
    1=0
    2=-12.6
    3=7.43 AC
    4=0
    5=0
    6=0
    7=0
    8=0
    9=0
    10=0
    11=0
    12=62.9

    AWM-103
    1=23.4
    2=79
    3=-80
    4=0
    5=13.6
    6=13.6
    7=-12.7
    8=-58
    9=-29
    10=-24
    11=-24
    12=0
    13=26
    14=26
    15=32.3
    16=63.3
    17=63.3
    18=5.3
    19=5.4
     
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  5. Watthour

    Watthour Electron Rancher - JS3600

    AWM-103? Import unit?

    If it were the AWR-103, the voltages appear to be well within tolerances:


    AWR-103
    1 = 23.4 √ (24)
    2 = 79 √ (76)
    3 = -80 √ (-79)
    4 = 0 √ (GND)
    5 = 13.6 √ (13)
    6 = 13.6 √ (13)
    7 = -12.7 √ (13)
    8 = -58 √ (-60)
    9 = -29 √ (-30)
    10= -24 √ (-25)
    11= -24 √ (-25)
    12= 0 √ (GND)
    13= 26 √ (25)
    14= 26 √ (25)
    15= 32.3 √ (30)
    16= 63.3 √ (60)
    17= 63.3 √ (60)
    18= 5.3 √ (5.4)
    19= 5.4 √ (5.4)
     
  6. Watthour

    Watthour Electron Rancher - JS3600

    The AWM-090 protection board numbers look correct, but more definition is needed for some of the measurements, specifically 4-11:

    AWM-090
    1 = 0 √ (GND)
    2 = -12.6 √ (-13)
    3 = 7.43 AC √
    4 = 0 (Recheck on 200mV scale)
    5 = 0 "
    6 = 0 "
    7 = 0 "
    8 = 0 "
    9 = 0 "
    10= 0 "
    11= 0 "
    12= 62.9 √ (60)
     

     

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  7. EastPoint

    EastPoint Factory Code No. 4200 Subscriber

    Messages:
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    Location:
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    Unplug both amp boards and see if it comes out of protection. If it does, then plug one in and see if it still does. If not, then that's your problem, probably those outputs and drivers. If it's not the amp board, it's probably the protection board or one of the two power supply boards. I just fixed an SX-1050 that wasn't coming out of protect. Turned out to be a really leaky cap on the underside power supply board.
     
  8. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    Let’s wait and see what voltages he’s getting on the protection board first.
    Still could be several things.
    Eastpoint:
    Not sure what you define as unplugging the amp boards(?).
     
  9. EastPoint

    EastPoint Factory Code No. 4200 Subscriber

    Messages:
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    Location:
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    Unhooking the molex connectors.
     
  10. kubotadave

    kubotadave New Member

    Messages:
    43
    Location:
    watertown ny
    Tried doing the molex connectors still stuck in protect
     
  11. kubotadave

    kubotadave New Member

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    Location:
    watertown ny
    1. =0 2= -12.6 3= 7.43 ac 4= 27mv 5=37 mv 6=61mv 7=68 mv 8=4.2mv 9=2mv 10=3.2mv 11=65mv 12=62.9volts
     

     

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  12. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    Please post voltages readings in this format, makes it easier to interpret.
    Nice job so far.

    1=0
    2= -12.6
    3= 7.43 ac
    4= 27mv
    5=37 mv
    6=61mv
    7=68 mv
    8=4.2mv
    9=2mv
    10=3.2mv
    11=65mv
    12=62.9volts

    Rebuild or repair the Protection board.
    Test the relay. Mouser P/N 653-MY4-02-DC48
    The coil should read around 2.2K ohms.
    Transistor Q7, the relay driver is a weak point in this circuit. The 2sc1384 is replaced with a robust KSC2690AYS.

    protection parts list.
    awm-090 c1 0.22 25 cssa x 0.22 50 598-DSF050J224
    awm-090 c2 0.22 25 cssa x 0.22 50 598-DSF050J224
    awm-090 c3 470 6 cea x 470 10 647-UPW1A471MPD
    awm-090 c4 470 6 cea x 470 10 647-UPW1A471MPD
    awm-090 c5 2.2 50 cea x 2.2 50 647-UPW1H2R2MDD
    awm-090 c6 47 50 cea x 47 50 647-UPW1H470MED
    awm-090 q1 2sc869 0 0 0 0 0 512-KSC1845FTA
    awm-090 q2 2sc869 0 0 0 0 0 512-KSC1845FTA
    awm-090 q6 2sc945 0 0 0 0 0 512-KSD1616AGBU
    awm-090 q7 2sc1384 0 0 0 0 0 512-KSC2690AYS
    awm-090 d5 eqa01-33r 0 0 0 0 0 512-1N5257B
    Relay, protection 653-MY4-02-DC48

    You could piece-meal it by replacing the transistors, working your way back from Q7.
    Replace the caps and relay as general practice.
     
    Last edited: Feb 5, 2019
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  13. merlynski

    merlynski Curmudgeon Electronicist Subscriber

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  14. kubotadave

    kubotadave New Member

    Messages:
    43
    Location:
    watertown ny
     
  15. kubotadave

    kubotadave New Member

    Messages:
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    Location:
    watertown ny
    Thank you so much for all the help.Its been 35 years since ive worked on electronics.The help and guidance shown on this site is invaluable.I have the parts ordered,and cant wait to rebuild.I want to push the contacts closed to see if sound is restored.Would this be a bad idea?
     
  16. kubotadave

    kubotadave New Member

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    43
    Location:
    watertown ny
    Could you tell me how to post the values in this format?Sorry im not great on a computer.
     

     

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  17. Watthour

    Watthour Electron Rancher - JS3600

    It's been 35 years since you've worked in electronics, so other than a little rust and dust, you should be fairly current with the vintage of units we tend to see. Once you get back on the bike and get your balance, you'll be golden.

    As for the formatting, simply enter one line, such as " 1 = 0V " then {ENTER} to start a new line/row.

    You're not great on a computer? Well, you found this site, and I believe that says SOMETHING about your prowess. :thumbsup:
     
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  18. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    First read post 19 before attempting this procedure.

    Make sure the jumpers are installed.
    With an input from the FM or AUX and the volume to a min level. Use your DMM in AC range and probe the pins 8 and 11 for a jumping voltage (Black to chassis) indicating the amps speaker output.
    While connected to pin 8 or 11, turn the volume up and watch the meter looking for an increase in voltage. Just a little to check the operation.
    If the indication looks good, you could jumper the pins:
    8 to 9
    10 to11
    A temporary check only.
     
    Last edited: Feb 5, 2019
  19. Watthour

    Watthour Electron Rancher - JS3600

    My feeling is that the 61/68mV on pins 6 & 7 could be at the threshold of tripping the protection.
     
  20. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    It could be
    Hold off on shorting the pins.
    Try to set the DC Balance using the service manual.
    You want to get the amp(s) as close to zero volts as it will let you.
     

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