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Sansui 5000X blowing left fuse....

Discussion in 'Exclusively Sansui' started by Wolverine, Oct 6, 2018.

  1. Wolverine

    Wolverine AK Subscriber Subscriber

    Messages:
    5,531
    Location:
    VA Beach Virginia
    So I got a Sansui 5000x free from the original owner a couple of years ago and really never used it as a daily driver for a variety of reasons. I hooked it up last week to use in a secondary system and the left rear fuse blew after a few minutes of playing. I am sure that there a variety of reasons that could be the cause but I was wondering based on the most likely cause what it will cost to get this up and running.
     

     

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  2. nosirrah

    nosirrah Moderator Staff Member Moderator Subscriber

    Messages:
    7,454
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    Fixed the title for you
     
  3. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    27,545
    Location:
    uk.. the middle bit
    output transistors etc .
     
  4. camfreak

    camfreak New Member

    Messages:
    7
    Do you know if it has the F-6013 driver boards or the F-1040-1 boards. Did you replace the fuse? If you did, did it blow again immediately or did it run for a couple of minutes again before blowing?
     
  5. Wolverine

    Wolverine AK Subscriber Subscriber

    Messages:
    5,531
    Location:
    VA Beach Virginia
    The known board issue with this receiver was corrected at some point in the past. The left fuse blows immediately at this point.
     
  6. camfreak

    camfreak New Member

    Messages:
    7
    At the very least you will have to replace the output transistors. A good sub for them is On Semi-conductor MJ21194G which are available at Mouser Electronics for $5.56 apiece. https://www.mouser.com/ProductDetail/863-MJ21194G They work well, I've been testing them thoroughly for use with my F-6013 clones I've been working on. Don't know your skill level troubleshooting amplifiers so let me suggest using a 'Load Lamp' after you have replaced them. A load lamp is simply a light bulb in series with the line cord. I generally use a 60 watt INCANDESCENT bulb, not an led or flourescent. You can still by them as a rough service bulb. If you still have a problem after replacing the outputs when you turn the unit on the lamp will glow bright due to the high current draw of the output section protecting your newly installed transistors. If everything is happy it will start to glow and then dim down almost completely. (depending on the amplifier) The 5000 will go practically out. If this happens chances are you are home free. However, there could be an underlying problem on the driver board that caused the outputs to short. I would also give your speaker cables a good inspection prior to testing. To make a load lamp go to your local hardware store and purchase a porcelain lamp base (like what you would use in a basement or shed) or equivalent and wire it into the line side of an extension cord. (be sure to insulate any exposed connection). After you have your 'load lamp' finished just plug the receiver into it and plug the other end into the wall. I've saved countless output transistors using this method. You will want to check and adjust if necessary center voltage (VR801) and bias current (VR802) after verifying everything is happy. You can do this initially while the load lamp is still in the circuit, just in case you have a bad pot. (I would also recommend cleaning them with DeOx prior to turning it on. Make a note of what position they are in and try to put them back in that position. If you don't then put VR801 in mid-position and Vr802 fully counterclockwise.) Finally remove the load lamp and readjust if necessary. Hope you're still awake!.The 'load lamp' is a great tool, however it will not work well with some amplifiers (DC amplifiers for example) It does work well with the 5000 though. Cheers,

    Phil
     

     

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  7. camfreak

    camfreak New Member

    Messages:
    7
    BTW if you decide not to repair this unit I would be very interested in acquiring it. They are good solid receivers that have stood the test of time well. The only real weakness they had were the driver boards which Sansui replaced for free if the unit came into the shop (warranty station). Unfortunately being as reliable as they are not all of them got the upgrade. Even though Sansui provided them for over 10 years there are still many, many units with the old 1040 and 1040-1 boards. That is why after finding it nearly impossible to find a pair of them I decided to make my own. They are in the final test stage now using transistors you can get off the shelf. (try crossing any of the original ones!) The quality of the PCB's themselves is first class and the passive components are all nichicon audio grade for the electrolytics and all resistor are 5% or better. The results are looking very good
     
  8. Wolverine

    Wolverine AK Subscriber Subscriber

    Messages:
    5,531
    Location:
    VA Beach Virginia
    Camfreak - Welcome to AK and thank you for all of the information. I am all thumbs when it comes to gear repairing but your information has given me the confidence that it can be repaired for not too much out of pocket.
     
  9. camfreak

    camfreak New Member

    Messages:
    7
    I'm glad I was able to help. Thanks for the welcome! I've actually been around AK and have been a registered user for as long as I can remember. The records don't reflect the correct date I enrolled. I need to do a profile and introduce myself. But that being said, if you follow my suggestions you should have no problems getting that unit back in good shape! I repaired my first 5000 in '79. I think the 5000 is among the best receivers ever built. And it really has a neat history. Sansui actually designed and manufactured the 5000 exclusively for american servicemen. It was only available in military PX's worldwide. And they sold a ton of them. Good luck with your repair!
     
  10. jberger

    jberger AK Subscriber Subscriber

    Messages:
    2,066
    Location:
    Long Beach, CA
    Phil, keep us up to date on the status of the F-6013 board cloning and testing.
     
  11. camfreak

    camfreak New Member

    Messages:
    7
    I will. As of now I've chosen the components that I'm going to use, I'll list the semi-conductors and if anyone has any suggestions I'm always open to them. I've tested these components quite extensively and am satisfied that they will perform well and be a reliable replacement for the original components. Actually the fabrication process has improved so much in the last 40+ years that I expect under normal conditions they will probably outlast us. I placed an order for the production boards today and expect them by late next week. I plan to make these available in with 4 different options. 1. Bare board 2. Bare board with output transistor sockets installed 3. Completely assembled and tested without output transistors 4. Completely assembled and tested including output transistors I will of course include all documentation and on option 1 and 2 include a complete BOM's so you can order the parts yourself. Or I could supply them with the boards as a kit. The transistors are as follows; TR801 = KSC1845, TR802 = KSC3503, TR803 = KSC2383, TR804 = 2N6316, TR805 = 2N6318. If anyone has a suggestion on how to mount TR803 to TR804 I would like to hear it. It is a TO92L package. I'm planning to use some .040 stainless shim stock to fabricate them at the presant time. That's about it folks. I'll update again as soon as things start coming together. I'm going to try and make time to do a profile on AK so you will get to know my backround. Happy Trails!

    Phil
     

     

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  12. Austy

    Austy New Member

    Messages:
    17
    I have a 5000a with the bad boards so hopefully you will do sales to the land down under?
     

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