Connect with us

Amplifier riddle, intermittent loss of output

Discussion in 'Electronic Repair' started by Kendrick S, Nov 25, 2003.

  1. Kendrick S

    Kendrick S Guest

    There are a few threads in the archives on this but I saw no
    definitive course of action other than "take it to a repair shop." I
    still might do that but that's not really why I'm here.

    Onkyo A/V Tuner Amplifier R1 loses output to right channel
    intermittently. All the following have occurred:
    1. The unit is turned on and there is only output to the left channel.
    This is what happens most frequently.

    2. The unit is turned on and there is output to both channels.
    Everything works, the stereo is a stereo; it happened this morning.

    3. The unit is turned on and there is output to both channels and
    then the right channel (and once even the left) disappears.

    I have swapped the speakers so the problem is not there. There's a
    big "click" a second or so after the unit is turned on which I take to
    be a speaker protection feature. Is it possible that there is a
    problem there? Any suspicions and simple test procedures will be
    appreciated.
     
  2. Bob Shuman

    Bob Shuman Guest

    From your description of the "click", I'd guess that this unit has a speaker
    relay that uses a time delay circuit to prevent undesirable power transients
    from getting to the speakers. Also your description of the problem could be
    explained by resistive relay contacts. Try increasing the volume when you
    see one of the speakers dropping out and see if the sound comes back once
    you reach the breakdown voltage. You can look at the signal going into the
    relay to see if you have a bad contact.

    If this is the case, then if you can open the relay you can try to
    file/clean the contacts, but in worst case may have to replace the relay.

    Good luck and hope this is your cause since it is a fairly straightforward
    replacement assuming you can find the replacement part.

    Bob
     
  3. Jerry G.

    Jerry G. Guest

    This may be the output stage protection relay, dirty contact in a switch,
    cold solder connection, or something similar.

    --

    Greetings,

    Jerry Greenberg GLG Technologies GLG
    =========================================
    WebPage http://www.zoom-one.com
    Electronics http://www.zoom-one.com/electron.htm
    =========================================


    There are a few threads in the archives on this but I saw no
    definitive course of action other than "take it to a repair shop." I
    still might do that but that's not really why I'm here.

    Onkyo A/V Tuner Amplifier R1 loses output to right channel
    intermittently. All the following have occurred:
    1. The unit is turned on and there is only output to the left channel.
    This is what happens most frequently.

    2. The unit is turned on and there is output to both channels.
    Everything works, the stereo is a stereo; it happened this morning.

    3. The unit is turned on and there is output to both channels and
    then the right channel (and once even the left) disappears.

    I have swapped the speakers so the problem is not there. There's a
    big "click" a second or so after the unit is turned on which I take to
    be a speaker protection feature. Is it possible that there is a
    problem there? Any suspicions and simple test procedures will be
    appreciated.
     
  4. Bob M.

    Bob M. Guest

    I had the same problem with my Onkyo receiver and replacing the internal
    relay DID cure the problem for several years. But now it has returned again.
    Increasing the volume control usually restores the defective channel, and it
    is mostly the right channel that quits.

    I did however discover that my receiver has a dynamic presence enhancer in
    it. What it does is a mystery, but the front panel push-on/push-off switch
    is dirty, and causes one or the other channel to cut out as it's pressed in
    and out. To get to it I need to disconnect and remove the receiver from my
    cabinet and pull the bottom and/or top covers off. I have tried to manually
    cycle it a bunch of times but that hasn't helped yet.

    I've also had problems with the two speaker pushbutton switches, again dirt.
    But what do you expect for a 20+ year old receiver?

    Bob M.
    ======
     
  5. R1 isn't the model number, it refers to Onkyo's proprietary system remote
    feature.
    The model number is on the rear panel, should read "TX-something" Like
    TX-84, TX-RV47, etc.

    A channel cutting out could be almost anything, but those who suggested the
    speaker relay may be right, especially if goosing the volume control makes
    the sound "punch through" temporarily.
    Also, try manipulating the various mechanical controls and switches - you
    may find one or more that affect your problem.

    Mark Z.
     
  6. Kendrick S

    Kendrick S Guest

    keep the "Oink, Oink" working and postpone going out and buying a nice
    new Rotel. But let's see....if I fix it, I can give it to my son when
    he heads off to college, and then....

    Have a great Thanksgiving,
    Kendrick
     
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

-