Marantz 4400 voltage for FM board

Discussion in 'Marantz Audio' started by daveyh, Aug 21, 2017.

  1. tonebells

    tonebells AK Subscriber Subscriber

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    Are you using something like this?





    [​IMG]

    Tony
     
  2. txturbo

    txturbo AK Subscriber Subscriber

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    Thats the exact part.
     
  3. tonebells

    tonebells AK Subscriber Subscriber

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    I will have to try that trick.

    Tony
     
  4. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    Be a bro (and you are!) and post what that test point is / source(s).
     
  5. daveyh

    daveyh AK Subscriber Subscriber

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    Last edited: Sep 30, 2017
  6. txturbo

    txturbo AK Subscriber Subscriber

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    rBuckner likes this.
  7. Steven Tate

    Steven Tate AK Subscriber Subscriber

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    Obviously everyone is loving your technique. I'm one of them. Dumb question -- what are you printing those connection numbers on? Is that just small cutouts of sticky sided label paper?
    Thanks for showing the technique. :thumbsup:
    Steve

    OK. Should have Googled first. I'll bet it was something like this. Right?

    https://www.bradyid.com/en-us/product/m21-125-c-342?catid=wbn_50174
     
  8. txturbo

    txturbo AK Subscriber Subscriber

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  9. Steven Tate

    Steven Tate AK Subscriber Subscriber

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    Awesome! I think I just started my Christmas wish list.:D
     
  10. daveyh

    daveyh AK Subscriber Subscriber

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    Bought a label printer like you have posted. It is awesome! Can do more than just print wire labels.

    I pulled all the wires from the board and labeled them. It is not a job for someone who has no patience. In fact, it took me a long time to cut, lengthen the wires, solder, shrink wrap them, put on test posts and solder and shrink wrap them. Quite a long effort! Around 5 hours!!!! I have still not installed the board!

    I recapped the FM MPX board and did all of the above.

    Is the anything else you would suggest I do before reinstalling the FM board?
     
  11. daveyh

    daveyh AK Subscriber Subscriber

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    I installed the board and still no stereo. Checked all the transistors and they were all good. I did not replaced the C305 film cap which is 470pf. I once had a Sansui 9090DB that had a 680pf cap that was bad iof the same type in the same area and I replaced it and the stereo lamp came on and I got stereo. Maybe I will try that. I should have replaced it to begin with. Now it's easy to pull the board. :thumbsup:

    Anyone know of somewhere in the Nashville, TN area that can align this?
     
  12. daveyh

    daveyh AK Subscriber Subscriber

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    Well none of the above has worked so far. I pulled the current P300 MPX board and installed another MPX board from another unit. Still no stereo lamp in FM and no separation. Everything else as far a CD and phono has stereo. I cleaned the tuner and still nothing. I know the lamp is good because it lights in Aux and phono mode.

    If I could just get it to work in stereo FM and get the lamp to light I would be done with this unit. :(
     
  13. Halisson

    Halisson New Member

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    Instructions for service manual:

    Symptom: No stereo separation.

    first check that the mode switch is in the normal 2ch position ...
    ... check that the stereo headlamp is on or not, check the 19khz JCH10 output signal using an oscilloscope and a frequency counter if it is not connected.


    Can you check the VDCs on HA1156? This IC may be the cause of the problem.
     
  14. daveyh

    daveyh AK Subscriber Subscriber

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    I have an oscilloscope but not a frequency counter. Checked the voltages on the HA1156 IC which seemed good and even tried installing a new HA1156 when I had the other board installed.Still no lamp.
     
  15. Halisson

    Halisson New Member

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    In my notes, I put an antenna, the FM signal was strong from a local FM STEREO radio, and the adjustment I made on the J301 coil, I remember that the FM circuit is delicate, so be careful with the position of this coil and it is very sensitive, the ideal is to do with the right instruments, it may be an option, but I did it at my own risk.
    It would be a long explanation and maybe my English would not help to help with an FM troubleshooting procedure, as well as the service manual.
     
    Last edited: Oct 6, 2017
  16. daveyh

    daveyh AK Subscriber Subscriber

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    Thank you for your post. I understand you and your English is fine. :thumbsup:

    I do get a strong FM signal from many stations but just not in stereo. I have tried adjustment of the J301 coil but no difference. I did notice my 400 tone control board does not make a tone when the button is pushed in and set to the correct settings. Would this have anything to do with the FM stereo not working?
     
  17. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    ^^^I doubt it.
     
  18. Halisson

    Halisson New Member

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    At one point, you would have other 4400 pieces, right?
    I think at some point there is a problem on the P200 board, because even there is an L201 coil, can you double check the board and confirm that everything is okay?
     
  19. daveyh

    daveyh AK Subscriber Subscriber

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    I tried adjusting the L201 coil on the P200 board. I was able to get less distortion and a cleaner FM signal. Still no stereo. I did not check the board for function.
     
  20. rBuckner

    rBuckner Luv 2 Restore Subscriber

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    What is the signal strength meter showing? If there's another problem, say the first FET in the front end is blown, the strength will be low and you won't get stereo even with no de-multiplexing issues. Also, if there's an attenuator switch on the back make sure it's on "out".
     

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