cd player project-troubleshoot audio drop out

Discussion in 'The Projects Forum' started by stuznu, Sep 19, 2013.

  1. stuznu

    Thread Starter New Member

    Sep 18, 2013
    Hi all,

    I am new member seeking any advice or guidance with a project I have taken up helping a friend troubleshoot, and hopefully repair his much loved Marantz CD63 player.

    The player in question has had a substantial amount of work done - capacitor upgrades, clock modification, regulator upgrades and has worked well for three years since the successful rejuvenation.

    After 3 years the player has now developed an audio dropout fault which occurs approximately 10-15minutes into playing a cd. A description of the fault would best be described in the following way:

    The problem:
    -Cd spins up on 'play', audio output at both speakers.
    -after 10-15minutes, popping soft hissing sound followed by a soft crackle
    -audio drop out.
    Cd continues to spin, counter continues to progress to other tracks.
    When stop button or fwd/back button is depressed cd will spin up again with audio,play a few minutes and drop out again.

    What I have tried:
    I first suspected intermittent thermal faults, dry joints and overheating problems so I tried freezing spray.
    Tried tracking back from outputs to DAC but found no variations in the outputs during play or at audio drop out.
    I have tried resoldering components, checked opamps, DAC, digital signal, laser and many other suggestions offered by experienced people on other forums.

    Used oscilloscope to check laser - eye pattern generated seemed steady and clear and complied with service manual specs.

    I have access to digital and analogue voltmeters, soldering iron(s), oscilloscopes x2, 20mhz and 50mhz as well as the schematic/circuit diagrams for the cd player.

    If anyone has had a similar issue and successfully diagnosed the fault it would be appreciated.

    Looking forward to your responses.

    Thank you
    Last edited: Sep 19, 2013
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
    Not sure what you mean by audio drop out. The sound just disappears?
  3. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    Dirty laser? Your symptoms are typical of poor laser performance or focus.

    The first few CD songs are near the centre and easier for the laser to track. As the CD plays the songs get further out on the disc, so spindle wobble etc gets worse in proportion to how high the song number is.

    You can try cleaning it, then if that doesn't work go over the service manual procedure for alignment etc, and in worst case laser just age over time and you might need a new laser module (and then align that too).
  4. stuznu

    Thread Starter New Member

    Sep 18, 2013
    Sound just disappears - always preceded by hiss/pop..... then silence..
    Dirty laser was suspected but after cleaning and switching the laser from my marantz cd player of the same vintage two things eliminated a dirty laser as the fault:
    -The laser from the faulty cdp played for hours without any drop out.
    -The fault persisted even when original laser was replaced with laser from my player.
  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    Hmm, sounds like you need the service manual and go over the test point waveforms and procedures. Some of those old Marantz CD players were absolutely full of adjustment trimpots... Not a nice job.

    As an interim measure you could get it hot until it faults, then try freezer spray on the ICs one by one and see if the fault clears (or makes some obvious symptom). That might let you diagnose a heat fault in a specific IC without needing the full service manual. :)
  6. wayneh


    Sep 9, 2010
    Or just upgrade to a modern blu-ray player for $50 and move on.

    Just sayin'
  7. stuznu

    Thread Starter New Member

    Sep 18, 2013
    I have a Sony Blu Ray player and Oppo95!

    This is a diy project that has full house mods. It is a giant killer even though it is over 10years old.

    A $50 player isn't in the ball park not even close..thanks for the suggestion though.
  8. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    This is not possible. If the audio is dropping out you WILL see a problem with the audio by backtracking from the audio output jacks. If you see good audio there then the problem is not IN the player.

    Go back and do the back track again. Start at the solder connections of the audio output jacks. If the audio has 'dropped out', then you will not see an audio signal here. If are seeing a good signal, then look at the equipment this output jack feeds.