Thanks Thanks:  13
Likes Likes:  22
Results 1 to 17 of 17

Thread: Sansui qrx 7001 keeps blowing rear leff fuses

  1. #1
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Sansui qrx 7001 keeps blowing rear leff fuses

    Hi,

    Finally I got a chage to hook up my 7001 yesterdad both left back outputs are blown

    I found a thread in this forum about the speakers fuses, checked them and they were blown, today I went and bought some, it keeps blowing them.

    If I put only one of the 2 fuses, it doesn't burn when I turn it on, but if I put both,they burn as soon as I turn the unit on.

    I appreciate any help.

    Thanks

  2. Likes Snood liked this post
  3. #2
    1K Club - QQ Shooting Star DuncanS's Avatar
    Join Date
    Aug 2012
    Location
    UK
    Posts
    2,312
    Points
    23,175
    Level
    93
    Level completed: 83%, Points required for next Level: 175
    Overall activity: 70.0%
    Achievements:
    10000 Experience PointsVeteranSocial
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    At a guess they are push-fit wires for your speakers, and it could be that your speaker cable is shorting to the chassis by the speaker sockets, or you have internal shorts in the Sansui.
    177 SACD (159 Multi, 18 Stereo), 218 DVD-Audio/DTS/DD, 10 Blu-ray Audio, 14 SQ LPs, 2218 plain old stereo CDs

  4. Thanks lev, Snood thanked for this post
    Likes lev, Snood liked this post
  5. #3
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Thank you DuncanS


    The speaker cables aren't shorting because they're the same I have been using with another reciever,actually, I am listening to them now.

    Will check the sansui for any shortings,

  6. Likes Snood liked this post
  7. #4
    500 Club - QQ All Star
    Join Date
    Dec 2005
    Location
    Houston, TX
    Posts
    513
    Points
    12,212
    Level
    72
    Level completed: 41%, Points required for next Level: 238
    Overall activity: 8.0%
    Achievements:
    VeteranCreated Blog entry10000 Experience Points
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Quote Originally Posted by lev View Post
    Hi,

    Finally I got a chage to hook up my 7001 yesterdad both left back outputs are blown

    I found a thread in this forum about the speakers fuses, checked them and they were blown, today I went and bought some, it keeps blowing them.

    If I put only one of the 2 fuses, it doesn't burn when I turn it on, but if I put both,they burn as soon as I turn the unit on.

    I appreciate any help.

    Thanks
    Since it works with either of the fuses in but not both, that suggests that wiring is not the problem or else the problem would be specific to one fuse. Unfortunately whether the specifics of the qrt 7001, so please take the following as a guess.

    This suggests some type of overall impedance issue, total power issue or thermal issue. All three of those are related in a way.

    What is the impedance of the speakers you are trying to use? Are the Sansui air vents covered or open? Can you try with different speakers?

    Unfortunately without testing the unit, it's hard to provide more than guesses about a cause.

    Andy

  8. Thanks Snood thanked for this post
    Likes Snood liked this post
  9. #5
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Thank you very much Andy,

    I tried it with infinity sm115 (8ohms)

    But it burns the fuses even without speakers.

    It is well ventilated,I also tried on top of the rack, and with the sansui's top off.

    Ivan

  10. Likes Snood liked this post
  11. #6
    1K Club - QQ Shooting Star DuncanS's Avatar
    Join Date
    Aug 2012
    Location
    UK
    Posts
    2,312
    Points
    23,175
    Level
    93
    Level completed: 83%, Points required for next Level: 175
    Overall activity: 70.0%
    Achievements:
    10000 Experience PointsVeteranSocial
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    That is very strange, as I wouldn't expect the fuses to blow if the speakers aren't connected as I would expect the fuse to be between the amp output and the speaker. Do you get a circuit diagram with the Sansui?

    Quote Originally Posted by lev View Post
    Thank you very much Andy,

    I tried it with infinity sm115 (8ohms)

    But it burns the fuses even without speakers.

    It is well ventilated,I also tried on top of the rack, and with the sansui's top off.

    Ivan
    177 SACD (159 Multi, 18 Stereo), 218 DVD-Audio/DTS/DD, 10 Blu-ray Audio, 14 SQ LPs, 2218 plain old stereo CDs

  12. Thanks lev, Snood thanked for this post
    Likes lev, Snood liked this post
  13. #7
    500 Club - QQ All Star
    Join Date
    Dec 2005
    Location
    Houston, TX
    Posts
    513
    Points
    12,212
    Level
    72
    Level completed: 41%, Points required for next Level: 238
    Overall activity: 8.0%
    Achievements:
    VeteranCreated Blog entry10000 Experience Points
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    I had one thought which is to verify that you have the right rating of fuses. Also, try to verify if you need regular fuses or delay action ones.

    If it is happening with an infinity ohm load (open load), then that eliminates the speakers as the cause. It makes me think there is a short in the unit. Maybe a cap has shorted?

    Andy

  14. Thanks lev, Snood thanked for this post
    Likes lev, Snood liked this post
  15. #8
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Quote Originally Posted by DuncanS View Post
    That is very strange, as I wouldn't expect the fuses to blow if the speakers aren't connected as I would expect the fuse to be between the amp output and the speaker. Do you get a circuit diagram with the Sansui?
    I don't have a diagram,but will try to get one.

    Thank you very much

  16. Likes Snood liked this post
  17. #9
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Quote Originally Posted by alk3997 View Post
    I had one thought which is to verify that you have the right rating of fuses. Also, try to verify if you need regular fuses or delay action ones.

    If it is happening with an infinity ohm load (open load), then that eliminates the speakers as the cause. It makes me think there is a short in the unit. Maybe a cap has shorted?

    Andy
    Thank you very much Andy, I will check that.
    Ivan

  18. Likes Snood liked this post
  19. #10
    1K Club - QQ Shooting Star DuncanS's Avatar
    Join Date
    Aug 2012
    Location
    UK
    Posts
    2,312
    Points
    23,175
    Level
    93
    Level completed: 83%, Points required for next Level: 175
    Overall activity: 70.0%
    Achievements:
    10000 Experience PointsVeteranSocial
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    There is often whats known as a Zoebel network (just Resistors & Capacitors) to modify the load seen by the amplifier as speakers will present a mainly inductive load (though this is modified by the cross-over filters in the speaker), so if this is post fuse it could be the problem.

    Quote Originally Posted by alk3997 View Post
    I had one thought which is to verify that you have the right rating of fuses. Also, try to verify if you need regular fuses or delay action ones.

    If it is happening with an infinity ohm load (open load), then that eliminates the speakers as the cause. It makes me think there is a short in the unit. Maybe a cap has shorted?

    Andy
    177 SACD (159 Multi, 18 Stereo), 218 DVD-Audio/DTS/DD, 10 Blu-ray Audio, 14 SQ LPs, 2218 plain old stereo CDs

  20. Thanks lev, Snood thanked for this post
    Likes lev, Snood liked this post
  21. #11
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Thank you Duncan,

    I was about to start packaging the 7001 to send it for guarantee, the seller told me he knew a technician who is really good, he has sold me a few more things and I have never had any issues, but the idea of someone I know nothing about tinkering with it gave the creeps haha,

    I will contact the QRX store to get it fixed, recapped, etc, I think sending it from Mexico is going to cost me a kidney , but I am sure it will be worth it

    In the mean time I bought a Sansui QR1500, and now I need t get at least one quad tape haha


    P.S.
    I removed the lower cover? today to see if there were any cables or hairs shorting something, everything looked ok, put 2 new fuses and now it blew 1 !!, I replaced it 3 times and it again blew only one...strange isnīt it?

    Kind regards,
    Ivan

  22. Thanks DuncanS thanked for this post
    Likes Snood liked this post
  23. #12
    600 Club - QQ All Star bigbillquad's Avatar
    Join Date
    Dec 2010
    Location
    New Zealand . Waitakere
    Posts
    685
    Points
    69,680
    Level
    100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 40.0%
    Achievements:
    VeteranCreated Album pictures50000 Experience Points
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Hi Ivan

    I think it would be best if you can let a Audio teck look at your QRX7001 as the saying goes a little knowledge is a dangerous thing, to keep putting fuses in can bring other problems in play.
    I bought a Sansui QRX80001 about 6? years ago and sent it to Jim Showker in the US. he has a web site ( qrxrestore.com ) he done a fantastic job I got him to do the full restore it cost me a leg & arm but the results are first class. So have a look at his web site I`m not saying send it to him just there is good information there to see.
    A locale man near where you live is the best..
    Bill..


    Quote Originally Posted by lev View Post
    Thank you Duncan,

    I was about to start packaging the 7001 to send it for guarantee, the seller told me he knew a technician who is really good, he has sold me a few more things and I have never had any issues, but the idea of someone I know nothing about tinkering with it gave the creeps haha,

    I will contact the QRX store to get it fixed, recapped, etc, I think sending it from Mexico is going to cost me a kidney , but I am sure it will be worth it

    In the mean time I bought a Sansui QR1500, and now I need t get at least one quad tape haha


    P.S.
    I removed the lower cover? today to see if there were any cables or hairs shorting something, everything looked ok, put 2 new fuses and now it blew 1 !!, I replaced it 3 times and it again blew only one...strange isnīt it?

    Kind regards,
    Ivan

  24. Thanks Snood thanked for this post
    Likes lev, Snood liked this post
  25. #13
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Quote Originally Posted by bigbillquad View Post
    Hi Ivan

    I think it would be best if you can let a Audio teck look at your QRX7001 as the saying goes a little knowledge is a dangerous thing, to keep putting fuses in can bring other problems in play.
    I bought a Sansui QRX80001 about 6? years ago and sent it to Jim Showker in the US. he has a web site ( qrxrestore.com ) he done a fantastic job I got him to do the full restore it cost me a leg & arm but the results are first class. So have a look at his web site I`m not saying send it to him just there is good information there to see.
    A locale man near where you live is the best..
    Bill..
    Thanks Bill, I will do it.

    I will contact the QRXstore, I am sure it will be worth every penny.

    Kind regards,
    Ivan

  26. Likes Snood liked this post
  27. #14
    600 Club - QQ All Star bigbillquad's Avatar
    Join Date
    Dec 2010
    Location
    New Zealand . Waitakere
    Posts
    685
    Points
    69,680
    Level
    100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 40.0%
    Achievements:
    VeteranCreated Album pictures50000 Experience Points
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Hi. Ivan

    I think you want regret it, but it will be up to your budget as how far you go to repair the 7001 unit.
    And remember the Sansui is a QS matrix unit so it will play QS LP`s better than SQ although it is still pretty good compared with other Quad units, the synth control on the 7001 does a great job on stereo music converting to Surround Quad really good most people have stereo LP`s or CD`s

    Quote Originally Posted by lev View Post
    Thanks Bill, I will do it.

    I will contact the QRXstore, I am sure it will be worth every penny.

    Kind regards,
    Ivan

  28. Thanks Snood thanked for this post
    Likes lev, Snood liked this post
  29. #15
    Junior Member
    Join Date
    Apr 2016
    Location
    Mexico
    Posts
    15
    Points
    420
    Level
    8
    Level completed: 40%, Points required for next Level: 30
    Overall activity: 0%
    Achievements:
    250 Experience Points3 months registered
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Quote Originally Posted by bigbillquad View Post
    Hi. Ivan

    I think you want regret it, but it will be up to your budget as how far you go to repair the 7001 unit.
    And remember the Sansui is a QS matrix unit so it will play QS LP`s better than SQ although it is still pretty good compared with other Quad units, the synth control on the 7001 does a great job on stereo music converting to Surround Quad really good most people have stereo LP`s or CD`s


    Thanks Bill, I have checked the price for restoring the 7001, and itīs all right I can afford it, just need to go sell a kidney haha,

    I need to talk to the UPS guys to see if it will go through customs without any problems from Mexico to the U.S., and if everything is ok, make a big sturdy box.

  30. Likes Snood liked this post
  31. #16
    600 Club - QQ All Star bigbillquad's Avatar
    Join Date
    Dec 2010
    Location
    New Zealand . Waitakere
    Posts
    685
    Points
    69,680
    Level
    100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 40.0%
    Achievements:
    VeteranCreated Album pictures50000 Experience Points
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    Hi. Ivan

    Well I hope everything works out for you .
    And remember when you get it back if you don't have any Quad LP`s just plug your CD or DVD stereo player into the front Auxiliary input press the Surround Synthesize Mood, of course you need 4 speakers connected to the 7001 & instant Surround Music you will be surprised .............surprised
    Bill.....


    Quote Originally Posted by lev View Post
    Thanks Bill, I have checked the price for restoring the 7001, and itīs all right I can afford it, just need to go sell a kidney haha,

    I need to talk to the UPS guys to see if it will go through customs without any problems from Mexico to the U.S., and if everything is ok, make a big sturdy box.

  32. Thanks lev thanked for this post
    Likes lev liked this post
  33. #17
    Member
    Join Date
    May 2006
    Location
    New Jersey
    Posts
    44
    Points
    8,815
    Level
    63
    Level completed: 22%, Points required for next Level: 235
    Overall activity: 0%
    Achievements:
    Veteran5000 Experience Points
    Post Thanks / Like

    Default Re: Sansui qrx 7001 keeps blowing rear leff fuses

    You have a shorted transistor in the output stage of that channel. It's either one of the heat sinked output transistors or one of the board mounted driver transistors. They will pull down the B+ voltage even without speakers connected and blow the fuses. If you can figure out which transistor is bad, you can order a replacement online for a few dollars, de-solder the bad one and solder in the new one.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •