Connect with us

KLH R3100 stereo receiver volume won't adjust

Discussion in 'Troubleshooting and Repair' started by bbullsj, Nov 28, 2018.

  1. bbullsj

    bbullsj

    12
    0
    Nov 28, 2018
    Only way I could get it to work is to open the picture and take a Snip of it.
     

    Attached Files:

    • 9.JPG
      9.JPG
      File size:
      102.3 KB
      Views:
      5
    • 7.JPG
      7.JPG
      File size:
      116.3 KB
      Views:
      6
    • 8.JPG
      8.JPG
      File size:
      129.8 KB
      Views:
      6
    • 9.JPG
      9.JPG
      File size:
      102.3 KB
      Views:
      6
  2. bbullsj

    bbullsj

    12
    0
    Nov 28, 2018
    Here are some more.
     

    Attached Files:

    • 2.JPG
      2.JPG
      File size:
      99.4 KB
      Views:
      5
    • 3.JPG
      3.JPG
      File size:
      56.1 KB
      Views:
      4
    • 4.JPG
      4.JPG
      File size:
      92.1 KB
      Views:
      5
    • 5.JPG
      5.JPG
      File size:
      98.8 KB
      Views:
      5
    • 6.JPG
      6.JPG
      File size:
      96.8 KB
      Views:
      5
  3. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    The two encoder channels end on the left two nodes out of 5 (solder lumps).

    What's directly on the other side of the board?
    Screenshot_2018-12-10-19-56-52-1.png
     
  4. bbullsj

    bbullsj

    12
    0
    Nov 28, 2018
    This big black component.
     

    Attached Files:

    • 6.JPG
      6.JPG
      File size:
      96.8 KB
      Views:
      9
  5. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    Looks like the microcontroller read/write pins 16 and 17.
    What's on the other side of here near the vol encoder?
    Screenshot_2018-12-15-17-38-24-1.png
     
  6. bbullsj

    bbullsj

    12
    0
    Nov 28, 2018
    these 2 resistors
     

    Attached Files:

    • 10.jpg
      10.jpg
      File size:
      193.4 KB
      Views:
      5
  7. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    No help there.
    I'd be looking at opamp 4558 which I think is this Screenshot_2018-12-18-21-14-46-1.png 8 pin component.

    Check power on pins 4(+) and 8 (gnd).
    Outputs pins 1 and 7, can be checked with an audio probe or amplified speaker with an isolator cap of about .1uf. (Google audio probe) The input can be checked similarly with an audio input fed to the receiver.

    One input side is pin 2 (neg)and 3(pos) and the other input is 5,6, The signal input (whether neg or pos) depends on circuit design.
    Try googling testing op-amps
     
    Last edited: Dec 19, 2018
  8. bbullsj

    bbullsj

    12
    0
    Nov 28, 2018
    How much is that part if it needs it?
     
  9. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    Under $1 plus shipping costs.
     
  10. Ylli

    Ylli

    200
    37
    Jun 19, 2018
    Do we have a schematic on this one? The 4558 is commonly used as the DC servo - making sure the outputs are centered at 0 volts.
     
  11. Ylli

    Ylli

    200
    37
    Jun 19, 2018
    Schematic of the KLH R3100, not the op-amp.
     
  12. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    No
     
  13. bbullsj

    bbullsj

    12
    0
    Nov 28, 2018
    Looks like a little more time than I want to spend in fixing it and have too much going on at the moment. Is it work anything to anybody in parts?
     
  14. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    Perhaps someone local.
    I like to post ads on craigslist or freecycle that say "free for parts or repair" Usually it's gone within a few hours.

    It's nice to see things get recycled/reused rather than going to the landfill.
     
  15. Tha fios agaibh

    Tha fios agaibh

    1,906
    600
    Aug 11, 2014
    ...And even more to find these ads so I can get free stuff to fix.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-