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B-1 Quickie

Discussion in 'Yamaha' started by rottalpha, Dec 11, 2017.

  1. rottalpha

    rottalpha Yamaholic

    Messages:
    1,810
    Location:
    Middle of Crook County
    will scan it for ya
     
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  2. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    Fantastic,

    Cheers. :D:thumbsup:

    Those are nice heatsinks :idea: What will special permission cost me?
     
  3. rottalpha

    rottalpha Yamaholic

    Messages:
    1,810
    Location:
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    makes a good Sunday afternoon read,

    or if you were to rebuild your B-1, this probably has more info than other places on the net....
    I had a hard time finding info on B-1 rebuilds when I decideed to take on the "quickie"
     
  4. rottalpha

    rottalpha Yamaholic

    Messages:
    1,810
    Location:
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    I am thinking maybe you could find out for us if those C rank SK180s of yours need further matching
    In the meantime, "technical" details of my patented heatsinks are somewhere on the first page of this thread, in my response to Bratwurst.
     
    vintagejapan likes this.
  5. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    Thank you Pete,

    Am waiting for some parts and should be firing up the beast soon.
    I have just completed the power supply boards 1&2.

    Will let you know how I go
     
  6. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    I also had a faulty MPSU60 on the power supply board 2 which I replaced this with a MPSW92.
     

     

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  7. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    Had to cut the heatsink for it, it is not much space in there
     

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  8. rottalpha

    rottalpha Yamaholic

    Messages:
    1,810
    Location:
    Middle of Crook County
    that would work.
     
  9. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    Well, the capacitor kit from Clinic is in. I have finished the power supply boards 1&2. A quick test and the-200 volt and +40 are showing up nice and steady on the power supply board #2. Also managed to adjust the 12v, -25 and +25 on power supply board #1. I have a weird issue though. When I turn off the power switch the amp stays on for few seconds. Then turns off. Not sure what to make of it.
    I checked the switch and the connection with the UC-1 and found no issues.
     

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  10. rottalpha

    rottalpha Yamaholic

    Messages:
    1,810
    Location:
    Middle of Crook County
    That main caps kit sure looks nice.:thumbsup:

    I think you are on the right track with troubleshooting. I would look at the switch and the protection circuit, including that solenoid.

    the question I have is how were you able to adjust the voltages if the power turns off so quickly??

    FYI, I powered averything up with a DBT and a variac, all the way to the driver boards.
     
  11. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    I think the power switch may be the culprit.

    When I turn the power ON remains on, but when I turn the power OFF just lingers for a couple of seconds before the power cuts off.
    The 3rd protection board is in, now the real fun begins...
     

     

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  12. rottalpha

    rottalpha Yamaholic

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    1,810
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    Say a prayer or two first, then watch those test leads.
     
  13. rottalpha

    rottalpha Yamaholic

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    What's taking so long:D
    Now I get to ask that question :beatnik:
     
  14. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    Well, the protection test went well last night.
    Just finished the filter board.
    Used 2SC1815 and 2SA1015 to replace the C458 and A763 transistors. Still need to source the relay.
    Also replaced some of the ceramic caps with silver mica.


    Pondering now on the first drive board.
     

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  15. rottalpha

    rottalpha Yamaholic

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    1,810
    Location:
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    man that driver board looks roasted
     
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  16. Vint Age

    Vint Age B-1 With Yamaha

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    2,221
    There are 2 types driver boards out there in B-1's, the more common light coloured ones and the rarer dark coloured ones.
     

     

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  17. rottalpha

    rottalpha Yamaholic

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    1,810
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    so he must have both, because look how light color is the one behind
     
  18. rottalpha

    rottalpha Yamaholic

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    Btw, there are at least 4 different B-1 iterations/updates faded on rear panel variations I seen so far
     
  19. vintagejapan

    vintagejapan AK Member Subscriber

    Messages:
    125
    Location:
    Queensland Australia
    The photo was from late last night and lighting was not ideal.

    VintAge is right, there are 2 type of boards and I am using a light one for the filter but dark green for the driver

    Here is a better shot of the driver board.

    Thank you Pete for your help with the heat sinks
     

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  20. rottalpha

    rottalpha Yamaholic

    Messages:
    1,810
    Location:
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    to me your driver boards looked diferent from eachother. I do not think is the lighting and I am not looking at the filter board...I am looking at two B-1 driver boards.
    Just an observation...
    driver boards.PNG
     
    Last edited: Jan 19, 2018

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