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Missing proprietary AV in/out cable - probing pins ok ? Hitach VM-H39A camcorder

Discussion in 'Troubleshooting and Repair' started by whiteoutage, Mar 12, 2019.

  1. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    So I got drafted to achieve our family Hi8 tapes. We lost the AV in\out cable so I have no way to dub tapes to my external, separate DVD recorder. This port in question has 20 bloody pins (see pics). Maybe I only need the 1 video and 2 stereo pins to output to an external recorder. Question I have is: Can I hook up my DVD recorder to AV cable(red,white, yellow) cut the opposite end of AV cord exposing 3 bare wires, play the old tape, then systematically and carefully probe 20 pins for sound and video?? Also not sure how I would know if I located, say a sound pin, when probing, while "dubbing"?

    PS - while playing tapes on camcorder I could view them though the viewfinder lens but could not hear sound. Maybe this model has no sound output while viewing from the camera. Also I searched the web for this darn cable - only found a substitute selling for $39 plus shipping.
     

    Attached Files:

    Last edited: Mar 12, 2019
  2. 73's de Edd

    73's de Edd

    2,616
    1,067
    Aug 21, 2015
    Sir whiteoutage . . . . .



    Faaaaaaaaaaaaar better, that you use the provided info below.
    First use the 14-18-9 and 3 ground connections in order to CORRECTLY decipher out the numbering sequence on that connector.
    Then the rest tells it all, by then just differentiating between which are inputs and which are outputs by monitoring..

    PRICELESS REFERENCING . . . . .

    upload_2019-3-14_12-26-2.png




    73's de Edd . . . . .


    I eat Swiss cheese from the inside out. But to fully mess up my wifes mind, I only nibble on it, by making its holes bigger.
     
  3. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    UPDATE: VIDEO OUT IS NOW COLOR (USER ERROR CONFUSED PIN 1 AND PIN 4)

    Fantastic, how did you find that - I looked everywhere?

    Ok, please keep in mind I am a bean counter wannabe electrician. I was able to map the pins per your instructions -thank you! Here is what I have found:

    1. Video out pin works to a TV's RCA yellow jack (via pin #4), however there is no color. I noticed there is a pin called chroma - if i short the chroma and video out will i get color? Pin 7 did not work so assuming it is video in. Not sure if it matters, but I think the lost cord in question had both regular video out and S-video out.
    2. None of the audio pins(15-16, 19-20) send sound to TV,'s red audio input, and coincidentally or not, there is no audio though the camera when previewing through the viewfinder -don't know if previewing through camera without sound is normal or not. Maybe this camcorder needs repair or I am not doing something correct pin-wise.
    3. I tried viewing on an alternate camcorder. A regular video 8 camcorder, not Hi8 like this recording was made on, and, sound played just fine though video was a total blue (bad video expected cause media is forward comparable but not backward as far as video is concerned).

    Anyone have any suggestions as to how I can get sound?

    PS If it matters I did both video and audio tests by cutting the red audio cable line and separating out positive red and negative white lines. Then probing both audio and video with it. I assumed the cords for video and audio are physically identical (ie 1 positive and 1 negative?.

    NOTES: 1. Original video was made on yet another Hi8 camcorder that also bit the dust.
    2.Anyone know if viewing video on camcorder should produce sound? Beginning to think this camcorder is also failing.
     
    Last edited: Mar 15, 2019
  4. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    Please ignore video issue No.1 above. - we got good video! Only problem remaining is no sound. Really don't want to take this thing apart cause I would have no clue as to how to troubleshoot a no sound issue, but that may be my only option with this camcorder?
     
  5. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    If i get perfect video on my TV when i put my test pin to the #4 pin video and my negative test pin to any ground pin (3,9,18).

    Then pinning my positive test pin to any one of these audio pins (15-16 or 19-20), and other pin to any negative ground (3,9,18) should get me one channel of audio on my TV.

    Please correct if my assumption if wrong.
     
  6. 73's de Edd

    73's de Edd

    2,616
    1,067
    Aug 21, 2015
    You done such a good job of loosing the AV cable assembly . . . . . did you do as well, in ALSO loosing its RF modulator which was also packed with that unit.
    It can also plug into that connector . . . . If so, then it would give you an AF modulated channel 3 or 4 TV signal which you could record from.
    I have the all schematics of the point of origin and distribution of the audio .
    But I don't think that you would have the skill set of tear down and troubleshooting of a Japanese rice farmers 18 yr old daughter, that worked in the HITACHI factory and initially honed her skills by extremely intense "monkey see- monkey do" training. To accomplish ONE production line task.

    I gave you the 2 in and 2 out pins on that connector for the audio . . .none of the others handle audio.
    You might have an auxiliary line in and line out option on the remote hand unit.
     
    Last edited: Mar 16, 2019
  7. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    You are probably not too far off about me troubleshooting this thing. Previously, Sansui mailed me a schematic - it took me a month of Sundays to find/replace the faulty transistor (a lightning strike sacrifice) on the front end of my 50 year old stereo tuner (a no AM sound repair). It was only by the grace of God and a very good electronics repair book that I even stumbled upon the faulty transistor. Regarding the remote, it has no input/output options - besides the video played out perfectly. A local repair tech told me last night that these camcorders are a beast to work on and recommended asking friends if they have one. Also learned that many of these camcorders had no sound output while viewing on the just camcorder itself. Hard to believe this unit retailed for $1300 back in the day and now, to me, is pretty much worthless.
     
    Last edited: Mar 16, 2019
  8. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    Just found out that the tape was not recorded on this unit but recorded on a regular video 8 unit (not Hi8). The original unit was stolen years ago, my sister bought this one used recently without in/output cords. So it is not Hi8 media but from what I read it still should play correctly in a Hi8 player.

    Are there any output voltage test that I can do on these pins?
     
    Last edited: Mar 16, 2019
  9. whiteoutage

    whiteoutage

    25
    1
    Jul 20, 2017
    The measured audio pin voltages are: - while playing a tape on the unit only (not hooked up to TV):

    pin #19 &20 initially output approx. 0.1 volts then drop to about .05 volts. Pins 15,16 show no significant voltages -possibly 15-16 are audio input pins while 19-20 are output?

    Other measured voltages:
    #1=3
    #2=5
    5=5
    8=6.8
    10=0.58
    11=5
    12=0.5
    13=5
    17=5
    other pins had no or trace voltages
    ???
     
  10. 73's de Edd

    73's de Edd

    2,616
    1,067
    Aug 21, 2015
    The ONLIEST other audio related connection is being the pin 13 an input related to dubbing in sound. In a situation where you wanted to add in sound where there was no sound before, WITHOUT erasing the VIDEO present WHEN you are adding the audio.
    OR you might not have liked the audio or needed to change a part of it out.
    The side arrows expain what connections or voltages / functions are being related to.
     
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