Servicing a SONY DAT machine (Pictorial)

Discussion in 'Tape' started by SaSi, Sep 17, 2008.

  1. jascha

    jascha Member

    Messages:
    79
    Location:
    Orpington, UK
    After my experiences dealing with a machine that had so many issues due to failed leaky capacitors I would start blaming them straight away. Not a job for the faint hearted however! If any of the caps leaked they could have damaged the board but for anyone with patience it can be a challenge to fix. I was lucky that I managed to fix mine. Having said all this it might be a case of connections not sitting quite right in their sockets and a case of spraying contact cleaner in case of oxidisation. If your technical skills are however limited it would be worth handing it to someone who ho can help you out as definitely the machine will need to be looked at inside. There might be other issues. Good luck
     

     

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  2. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    @vinylgenie
    At this stage I will suspect the power supply. Check all outputs according to the service manual.
     
  3. vinylgenie

    vinylgenie New Member

    Messages:
    3
    Thank you for taking the time to reply. I wouldn't be trying anything so complex myself. Its very useful to have an opinion before I take it to a repairer.
     
  4. vinylgenie

    vinylgenie New Member

    Messages:
    3
    Thank you! This is something I can try. Your time spent replying is appreciated.
     
  5. uzvarb

    uzvarb New Member

    Messages:
    21
    Location:
    Serbia
    55es head hours.jpg Thanks to Hdrobien I have good RF amp for dtc-55es. Now playback is perfect, recording on DDS (1,2,3) also perfect. Byt on DAT tapes not. When recording on new dat tape problem is still there. Sounds like bad and scratched vinyl. Finaly I decided to drill a hole on rm-d55a and try secret button for various test mode. Head hours is only 36 hours, but door openings is more then 3000...
    Reseting on 55es is impossible on easy way or incidentally.
    I don't believe is counter go to the end and count again, no way to playback work after 10036 hours...
     
    Last edited: Apr 15, 2017
  6. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    On most Sony DAT the head hours counter can be reset by modifying the DPG adjustment.

    Have you tried several DAT audio tapes ?
     

     

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  7. uzvarb

    uzvarb New Member

    Messages:
    21
    Location:
    Serbia
    I'm pretty sure that no one has set up DPG. The owner before me used it only as a DAC. What changes DPG specific parameters, and does that mean that it is not possible to switch mechanics from one to another without these settings. Earlier I changed mechanics between dtc59es and 60ES and there were no problems.
    Going back to the 55es. I changed capacitors on a new RF amplifier and the situation is finally right. Also came the long-awaited piece of 55es with rewind problem. Mechanics I serviced, but the problem is still present until the dat is warm. Something is in trouble on the main board because both the mechanics work without problems in the first DAT. Swapping the power board has not made any changes.
    Otherwise problem with recording is present on the second machine with the problematic tape. The conclusion is strange, the tape is not compatible with 55es ..xaxaxax
     
    Last edited: Apr 22, 2017
  8. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    Not sure to understand about the recording issue. Did you have to replace the capacitors on my rf amp to get it right ? Or it is, in fact, a tape problem ?

    About the DPG setting I agree that it does not change things, and I have never had any problem swapping mechas.
     
  9. uzvarb

    uzvarb New Member

    Messages:
    21
    Location:
    Serbia
    To the RF amplifier that came from you I changed the capacitors, setting your RF has solved all the problems with reproduction, but it remained a problem in the recording, the problem was much smaller than with a original rf amp.
    When I changed capacitors, only occasionally a problem occurs. But completely identical acts on other dat 55es with this type of tape. So definitely this kind of TDK tape does not match dtc-55es, or a problem in a particular series of tapes because I have 3 new and all have identical problems.
    All other types of work normally.
     
  10. uzvarb

    uzvarb New Member

    Messages:
    21
    Location:
    Serbia
    On that second DAT rotary encoder is make problem, cleaning with contacts cleaner is not enough. Disassembly and polishing contact will prevent gear destruction.
    After I see how the contact looks, I clean it and on first DAT.
     

    Attached Files:

  11. digitalfever

    digitalfever New Member

    Messages:
    5
    Hello everyone!

    Does anyone have the service manual for the JVC XD-Z1010 or Victor XD-Z900 by any chance?

    I'm having some problems with the analog output, digital seems to be working fine and it seems a bit tricky to find a way around the problem without the manual....

    Any help would be highly appreciated, thank you in advance!
     

     

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  12. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    Hi

    I had a similar problem with a XD-1010. Didn't find a solution.

    My understanding is that there are 4 converters PCM1701P, 2 per channel, one is for the 8 lower bits, the other for the 8 higher bits.

    On my unit, one channel was only playing the 8 lower bits, the other the 8 higher bits.

    My best guess is that the circuit in charge of splitting the signal between the converter is faulty. This circuit is the proprietary JVC K2 interface.

    Btw I have the service manual.
     
  13. jascha

    jascha Member

    Messages:
    79
    Location:
    Orpington, UK
    After a few months I’m back to report that the remote control function on the 2700 is now up and running. A simple delay relay has been put into action which when active shorts pins 23 and 27 to ground (pin 20). When the clock timer comes on to turn on the machine it simultaneously turns on the relay which after 5 seconds shorts the 3 contacts together and puts the machine in record mode :). I attach 2 pictures to show. On the relay contacts Pins 23 and 27 are shorter together always and when the relay clicks in it shorts them with the ground connection. On the 37 pin remote plug I inserted a toggle switch which cuts out the earth connection. When I need the timer function I switch it to on which means the earth is continuous. In off mode the earth connection never reaches the relay so it will never go into record when switched on! :).
     

    Attached Files:

  14. d-roby

    d-roby Member

    Messages:
    69
    Location:
    Genova- Italy
    Hello... thank you VERY much for detailled explanations..

    I have a 59ES DAT that had some transport problems...it was very slow and sometimes it stopped..
    then i took it apart and i changed the spooling motor. I checked the old one an it was not ok, very low power

    [​IMG]

    Replacement motor is from a cd-rom unit, very common type..

    [​IMG]
    [​IMG]

    also i changed SMD capacitors of the RF board


    [​IMG]
    [​IMG]
    Now the deck works fine. playback, record, index search, ecc; i recorded a tape and played back on a Fostex DAT with error rate display and is very good

    REW and FFWD now are very fast (may be too fast? ) but there is a problem.. in rew, at the middle/end of the tape it is noisy, and expecially in ffwd i can hear a "tic tic", may be a solenoid, i do not know
    i made a short video: i apologize for the quality of the video (and sorry for my english, lol)




    What do you think about?

    any suggestion about how to look for the problem ? brakes, clutch?
    Many thanks in advance
    Roberto
     
    Last edited: Nov 20, 2017
  15. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    Not sure but I believe it is the tape that's trembling due to lack of back tension during rewind.
     
  16. d-roby

    d-roby Member

    Messages:
    69
    Location:
    Genova- Italy
    Thank you.. so ..do you think it is a problem of FWD back tension adjustment? (on the side of the mechanics)
     

     

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  17. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    No, the adjustment screw on the side of the mecha is only for playback.

    During fast forward and rewind the back tension is generated by the reels themselves. But sometimes the back tension is too weak, and the tape starts trembling.

    When the "tic tic" occurs, look at the tape exiting the cassette shell, near the capstan.
     
  18. d-roby

    d-roby Member

    Messages:
    69
    Location:
    Genova- Italy
    Many thanks..i will take a look
    i suppose i will have to dismant the whole mechanics.. ;-)
     
  19. hdrobien

    hdrobien Active Member

    Messages:
    488
    Location:
    France
    No. I believe that you can see it from behind or above (trough the loading mechanisme).
     
  20. d-roby

    d-roby Member

    Messages:
    69
    Location:
    Genova- Italy
    yes.. but i was talking about dismanting if i want to investigate the problem.. i suppose brakes. or .there is a "clutch" inside the reels, right? Or some point that need lubrification (what kind of lubrificant? very small quantity of lithium grease or what? (generally speaking)?
     

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