SANSUII BA-3000 PROBLEMS

Discussion in 'Exclusively Sansui' started by pppoffice, Aug 30, 2017.

  1. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    Our quite old Basset Hound Female just loves food. When I get home for dinner she starts in on me for treats. She has been starting to put on some pounds so my wife doesn't want me to give her the normal 3-4 treats I give her when I come home for dinner. I don't see this dog that much as I am over here working on something all the time so I like to try to make it up with treats. I miss giving her the treats as much as she misses getting the. We are both animal lovers and I do mean ALL animals.
     
  2. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    I have about an hour before I have to go to dinner if you want to get something done now. I will be back after dinner to work a while but not as late as normal because mowing for 6 hours tomorrow takes a lot out of me.
     
  3. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    I'm headed over to my shop until dinner time. I will check back after dinner to see if you want anything checked.
     
  4. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    Can you repost these results
    Test TR 11 & 16??
    Passive test:

    TEST TR 12 & 15
    R-33,34 ( THAT 1 K IN THAT LADDER MARKED R-24 ) R-35
     
  5. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    I didn't see that this thread went up to page 15 !!!
     
  6. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    I know about not seeing that this has went up to another page. I have to remember to look for that. TR-12 & TR-12 tested just fine as did TR-11 and TR-16. R-33 had already been replaced by a MF. The readings I got after changing TR-14 are as follows. The big Caps tested +70.8 VDC and -70.8 VDC. The B+- was +87.3 VDC and -87.4 VDC. The 60 volt section was +70.8 VDC and -70.8 VDC. The 35 volt section (which is back after changing TR-14) was +16.9 VDC and -16.1 VDC. I think if we could get that 35 volt section up to where #1 Board is at which is around +-34 VDC that we could move on to the 2507 Driver Boards. RIGHT?
     
  7. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    I am going over to my shop to work for a while. I will check back in a bit to see if you have anything you want me to check. I won't be staying up as late tonight so if I don't hear from you some time pretty soon this evening the amp will have to wait until Friday.
     
  8. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    You meant TR 12 & 15? were ok?
    Still do not have data on my sheet for :
    R-33,34 ( THAT 1 K IN THAT LADDER MARKED R-24 ) R-35 R-28 & 29

    If all those are good
    Replace ZD-02
     
  9. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    Do you have a scope on the workbench you are working on?
     
  10. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    I am almost 100% sure that I tested all of these resistors for you. I know that I told you that R-33 was already changed to a MF resistor so I'm positive that I tested all of these other transistors. I remember because they are all grouped up in that little cluster and are a bitch to get at. I can't replace ZD-02 unless I rob the one in Board #1. I have some of the cross ref. diodes ordered but they are not here yet.
     
  11. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    My Tektronix Model 465B is on its rolling cart on the other side of my 3000 sq. ft. shop. Like I told you before, I am not up to speed on using it. I can get square waves and sine waves but that's about all. I have no idea how to read it. When I traded a Collins receiver for this scope it came with everything but the kitchen sink. I think it has 3 or 4 sets of Tektronix leads and other goodies. Before I stop for the night I will check those resistors again for you.
     
  12. sregor

    sregor AK Subscriber Subscriber

    Messages:
    3,071
    Location:
    Mass
    15.4
    +1 on this!. The way the circuit works, with all good components, the output voltage will be approximately 2.2 times the zenervoltage + 1 diode drop - approximately 7* 2.2 which is 15.4 depending on the exact values of r28 and r29. 15 volt zener results in 34.5. On the first board, there was not enough current to reach the zener voltage, but here it appears you have enough so the zener may test good, but I believe it is wrong value. my 2 cents.... (however I've been wrong before.) carry on.
     
  13. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    Soooo, how do you want me to carry on? Did you mean change out ZD-02 by robbing it from #1-2508?
     
  14. sregor

    sregor AK Subscriber Subscriber

    Messages:
    3,071
    Location:
    Mass
    Your choice. Waiting for the parts is fine. It would prove me right or wrong, but instant gratification isn't necessary. I was going to suggest the one from the 60 volt supply, but it may be off too. (actually, would be a simple way of testing that one, too.)

    As an aside, most testers don't put out a high enough voltage to measure the zener voltage (but I'm not familiar with any of the new ones, except the cheap ebay one which doesn't). Standard practice would be an external supply and a current limiting resistor, and measure the voltage directly. Something 20 to 30 volts and a resistor which would limit the current to 1 or 2 mA. (30 volts 15k resistor for checking zener voltage) My 2 cents.
     
  15. pppoffice

    pppoffice AudioBear Subscriber

    Messages:
    374
    Location:
    South of KC, Missouri
    I just went back to look at post I made. I found on page 13 my reply to test all of these resistors you wanted checked out. Here is my reply. "All of the transistors and resistors checked just fine and R-33 is now a MF." So as to not waste any time, I am going over right now and rob ZD-02 out of #1-2508 and put it into #2-2508. I will then take new readings for you.
     
  16. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    Mike we need to be specific, so when I ask for X,Y,Z ( and have to cruise back thru10+ posts ) and I get it's all ok.....it gets a bit much... as as seen I'll miss it.
    Remember I'm ~ 2000 miles away and I can't see what you are seeing...
     
  17. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    So You can rob from Board 1 OR I thought you had a sub zener in your stash? ( Not the new order stuff)
    It just needs to be a ~ 14 volt zener
     
  18. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    Your working zeners tested like this ZD-01=UF 913Mv C=61 which was not what you got on #2 board
     
  19. sregor

    sregor AK Subscriber Subscriber

    Messages:
    3,071
    Location:
    Mass
    15 volt
     
  20. vigman

    vigman SUBSCRIBER

    Messages:
    3,854
    Location:
    Valencia CA
    As far as the scope goes we just need to verify 1 channel at a time , like a 1K sine wave from an audio generator which I assume you also have....
     

Share This Page