1. Time for some upgrades in server hardware and software to enhance security and take AK to the next level. Please contribute what you can to sales@audiokarma.org at PayPal.com - Thanks from the AK Team
    Dismiss Notice

Burning resistor ( SA1000 ps board)

Discussion in 'Pioneer Audio' started by The Fuxtor, May 16, 2018.

  1. The Fuxtor

    The Fuxtor AK Subscriber Subscriber

    Messages:
    2,707
    Location:
    Calgary, Alberta
    Been restoring a Pioneer SA-1000. Got to the main amp boards and after completing caps and transistors fired it up for a test under DBT and discovered R1 ( 330 ohm) on the power supply board started smoking. Before I start checking components on that board, what would my best/ logical approach be? The pioneer service manuals are excellent as far as details go , thinking maybe I'm missing something obvious??
    EDIT: my bulb dimmed out on power up. Also the power supply board has been recapped already and re-transistored.... After completing that board I checked the unit with the dbt but just briefly to confirm no shorts...
     

    Attached Files:

    Last edited: May 17, 2018

     

    Please register to disable this ad.

  2. The Fuxtor

    The Fuxtor AK Subscriber Subscriber

    Messages:
    2,707
    Location:
    Calgary, Alberta
    I was thinking D5 is shot, but wouldn't that be indicated by a bright bulb?
     
  3. llwhtt

    llwhtt Super Member

    Messages:
    1,450
    Location:
    SoCal
    That's the -45VDC supply for the amplifier input diffs and VAS stages. Recheck your work on the amplifier boards as that's the only place the -45VDC goes.

    Craig
     
  4. The Fuxtor

    The Fuxtor AK Subscriber Subscriber

    Messages:
    2,707
    Location:
    Calgary, Alberta
    Thanks for that info! I seen that pin 13 (? ) was coming from amp board running -45v , but couldn't connect .....
    Anyway I indeed had a set of transistors put in with wrong sub... Seems all good again. I would have been checking that ps board for a week!
     

Share This Page