1. Rest in Peace Paul (Kegger) If you would like to help the family in this time of great sorrow and need, you may donate on their GoFundme page: https://www.gofundme.com/mckechnie-medical-and-funeral-fund?
    Dismiss Notice

Right Speaker (STEREO) Goes Out After A Few Minutes

Discussion in 'General Audio Discussion' started by Kevbo, Mar 20, 2017.

  1. WaynerN

    WaynerN Super Member

    Messages:
    3,615
    Location:
    Minnesota
    The good news is that you have found the culprit. Zero in on him when you have time and get some Deoxit on those contacts (if you have any). I think jiggling it is just making the contacts not contact so well. Keep pushing it in and out.

    Lesson for many here, if you have any kind of preamp or receiver with tape monitor loops and things like that, every once in a while, run them in and out a bunch of times.....
     
  2. onplane

    onplane What! No Wake???

    Messages:
    2,016
    Location:
    Rochester, NY
    Wayne, there has to be a switch somewhere to disable the pre to power amps internal connections. (He runs the unit with no jumpers.) Do you know where the switch is?

    Regards,
    Jerry
     
  3. WaynerN

    WaynerN Super Member

    Messages:
    3,615
    Location:
    Minnesota
    I don't know how its done. Maybe there is a break/make connection in the pre and amp RCA jacks???????

    Why would inserting a cable make it work? The other receivers that I have seen had the u-shaped jumpers.........I plead stupid on this one.

    Hell, even my fairly new Marantz SR-4021 has jumpers........
     
  4. Kevbo

    Kevbo New Member

    Messages:
    37
    So here is a shot of the inside. What you are looking at is the Main In and Pre Amp. Since this is looking from inside the bottom, the connectors on the top with the white wire is the Right Main In (connector on left) to Right Pre Amp (connector on right). So the connectors underneath in the other pictures are the Left Main In (connector on left) and Left Pre Amp (connector on right).

    Now, it may be hard to tell, but doesn't it look like all four of these are connected amongst all these wires? Is that how it should be, or was this an after market "repair". So with all these wires, is that why I have no need for jacks in the back?
     

    Attached Files:

  5. onplane

    onplane What! No Wake???

    Messages:
    2,016
    Location:
    Rochester, NY
    Wayne was right. The rca jacks on the main-in are a make/break connection. It's just like the headphone jacks that break the speaker path when the headphone jack is inserted. (In this case those white wires are the audio signal and you can see clearly where the signal crosses from the pre-out to the main-in. This is clever, but all of these make/breaks are subject to oxidation. It's clever, because you can run the internal power amp and another power amp - say in a bi-amp - WITHOUT the need for Y's. )

    Work it. Spray it. Work it again.

    Regards,
    Jerry
     
    Last edited: Mar 20, 2017
  6. BOUXY

    BOUXY Super Member

    Messages:
    4,269
    Location:
    WPG,MB CANADA
    My 2385 works with or without jumpers.Has an internal switch to allow this:)
     
  7. Kevbo

    Kevbo New Member

    Messages:
    37
    Well, I just sprayed it quite a bit and worked it almost a hundred times. And it seems to be working! I don't even get a crackling sound anymore when I wiggle the button. Keeping fingers crossed, this may have fixed this! Thank you all so much! I can't thank you enough. And thank you to my dad for helping me with all the repairs prior and helping me try to figure this out. I think I like this whole "forum concept". :) Having experts at your fingertips is quite amazing. If anything else comes of it, I will repost, but I think we may be good. Still a little early, but with no crackling sound anymore the speaker not going out, I will be optimistic about it.

    ~Kevin
     
    mech986 likes this.
  8. Kevbo

    Kevbo New Member

    Messages:
    37
    Do you know where that internal switch is located? Would it be around the area that I posted this pictures from? By the Main In and Pre Amp jacks?
     
  9. BOUXY

    BOUXY Super Member

    Messages:
    4,269
    Location:
    WPG,MB CANADA
    Sorry I don't:)
     
  10. onplane

    onplane What! No Wake???

    Messages:
    2,016
    Location:
    Rochester, NY
    The "switch" is inside the rca jacks. See my earlier post.

    Jerry
     
  11. Kevbo

    Kevbo New Member

    Messages:
    37
    Ahhh, yes. You're right. My apologizes. A few posts came in around the same time and I must have missed that. Sorry. That makes complete sense!
     
  12. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

    Messages:
    27,462
    Location:
    Central Missouri
    Here's a good view of this type of jack.
    [​IMG]Not an RCA but the concept is the same. When you plug something in, its center pin hits that inverted V contact in the middle, thus pushing it downward, disconnecting it at the bottom where it's touching that little button on the other piece. You can see how that little button or the spot it touches could get corroded pretty easily.
     
    gtv2000 likes this.
  13. Kevbo

    Kevbo New Member

    Messages:
    37
    @toxcrusadr Thank you for that! Makes much more sense now that I see it. Thank you. And to everyone else, I am home from bowling, and I still had the Marantz bottom open to let it dry while I was away. I fired it back on, and all seemed well. However, when I did wiggle the Tape Source switch, there was some minimal crackling and the sound went out again, but came right back on with the slightest touch. It doesn't seem anywhere near as bad as before, but could I assume the De-Oxit is doing its job, I just have to spray on more and let it continue to break up the corrosion? Also, is there any such thing as spraying too much De-Oxit, not necessarily all at once, but over a couple times? Can it hurt anything in the receiver if I spray quite a bit, let it dry, and come back and spray more?
     
  14. KingBubba

    KingBubba "Too Much Stuff" Subscriber

    Messages:
    8,244
    Location:
    Brooksville, Fl.
    Some times it can take more than 1 application. It also helps to do the working of the switch when the Deoxit is freshly applied. Also,Caig recommends that an application of Gold or Shield following the Deoxit drying will help keep the corrosion from returning. Gold can be used in cleaner locations and Shield should be used in more corrosive locations, like Florida, with it's months of 90% - 100% humidity, or living near the ocean or dusty locations.
     
  15. blhagstrom

    blhagstrom Mad Scientist, fixer. Subscriber

    Messages:
    11,996
    Location:
    Duvall, Washington
    The problem is getting deoxit into the switch. They are sort of sealed.
    I have drilled holes in the back to get juice into them. It's a trick move that takes skill.
    Try squirting down the shaft with the unit tilted back.
     
    mech986 and dlucy like this.
  16. Kevbo

    Kevbo New Member

    Messages:
    37
    @onplane I guess my question is, since I have the internal connections that make it so I don't need the jumper cables (jack) from pre amp to Main In, was that a factory thing done by Marantz or after market? If it was done by Marantz, then what would even be the point of having those jacks in the back? In fact, if Marantz didn't do it, why wouldn't they just to save the trouble of having those jacks?
     
  17. onplane

    onplane What! No Wake???

    Messages:
    2,016
    Location:
    Rochester, NY
    Correct! Kevin, you do NOT need jumpers from pre-out to main-in as is required in most amps. Undoubtedly those internal make/break connections were installed by Marantz to make life easier for their customers. Just check this forum for the number of people who lose or misplace their jumpers. Then there are a number of people who experience corrosion in the jumpers as the metals in contact are dissimilar.

    The point of the jacks and they are a very nice thing to have is flexibility. These jacks allow you to use the Marantz's pre-amp as the input to another power amp. Supposing you had a super 500 watt power amp, but you still wanted an excellent pre-amp feeding the signal to it. That's what the pre-out is for. In addition, supposing you wanted to bi-amp your speakers and have a single volume control. In this case, like above, you'd feed the pre-out to a strong power amp to drive the woofers and you'd use the power amp in the Marantz to drive the high frequency drivers.

    Finally, Kevin, the main-ins allow you to use the Marantz's power amp without having to use its pre-amp. For example, supposing you like the sound of tube amplifiers, but don't have a tube amp big enough to drive your particular speakers. You could use a tube pre-amp as the input to Marantz's power amp. This way you could achieve that "warm tube amp sound", yet still have sufficient power to drive your speakers.

    In short, those jacks provide enormous flexibility and are a good thing to have.

    Regards,
    Jerry
     
    Last edited: Mar 21, 2017
  18. bill114

    bill114 AK Subscriber Subscriber

    Messages:
    236
    Location:
    Seminole, FL
    mech986 likes this.
  19. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

    Messages:
    27,462
    Location:
    Central Missouri
    I always stuff a rag under whatever I'm spraying to soak up the excess and keep it from getting all over the boards. DeOxit (apparently, I can't prove it) is 5% oleic acid which is just a fatty acid that is a main constituent of vegetable oils. This oily part will not evaporate away very fast and can soak into phenolic boards, I would think.
     
  20. Kevbo

    Kevbo New Member

    Messages:
    37

Share This Page