Amp going into protection mode with rear channels

Discussion in 'AV Receivers' started by Girish, Feb 2, 2005.

  1. Girish

    Girish Stunt Coordinator

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    I have my proceed pav/pdsd hooked to Harman Kardon signature 2.1 amp driving the speakers. The L,R, and Center are working fine. When I try increasing the sound level of rear speakers the amp goes into protection mode. There is no sound coming from rears at low levels. The same thing happens while the rear speakers are disconnected, so there is nothing wrong with the speakers. When connected and I check the sound levels on the speakers I hear a popping noise when I go to the rear speakers but no sound. The wires going to the rear speakers are new and fine. Same problem persists when I hook a different amplifier and different sets of speakers in the rears.
    Where else the short can be in the preamp????
    BTW teh wires connecting the preamp and the amp are fine.
    Harman wants $1300 to look at the preamp.
     
  2. Girish

    Girish Stunt Coordinator

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    well I opened the pdsd and found a blown resistor on the rear channel circuit plate. Now is there a way to fix it without sending it to a one way trip to harman??
     
  3. John S

    John S Producer

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    Visably damaged components?? Ahh heck, if out of warranty, I'd probably just take it down to a local tech type and see what he can come up with. Of course, I would probably just do it myself, but I are sposed to be "Qualified Technician" of course that degree was obtained in 1982, I'm an I.T. puke now. [​IMG]
     
  4. Chu Gai

    Chu Gai Lead Actor

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    Assuming it's just the resistor, then identify its rating and solder another in place. 'Course, one might ask the question what caused it do this. Other than that, I'd just look for a local electronics repair shop in the Yellow Pages.
     
  5. Girish

    Girish Stunt Coordinator

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    what kind of local tech types are you suggesting. I have pretty good soldering skills but to find the resistor and to see if anything else is fried along the circuit is where I need help.
     
  6. John S

    John S Producer

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    Anybody that repairs, amps, and general electronics work.


    Usually you can find the resistor value by looking at the other stages of the pre-amp, it should be uniform across the different channels.
     
  7. Girish

    Girish Stunt Coordinator

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    harman says if i can give them the transistor number they can tell me what it is and where to get.
     
  8. John S

    John S Producer

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    Well heck, give it a shot!!!! analog stages in such equipment, isn't usually difficult to repair / figure it out. Often just going down the stage with a simple VOM wil reveal the bad component(s).
     
  9. Girish

    Girish Stunt Coordinator

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    I replaced the resistor but the sound is cracking. I am sure there is a short around that resistor. There are two similar circuit boards in the unit(One for L,R, one for C and sub). If I swap one of those the sound is perfect. So the fault is in that analog plate. I am sure it should be an easy fix for someone with the right tools. I will try to find a techinician who can do that.
    Definitely not worth the money and wait to send it to harman.
     
  10. Chu Gai

    Chu Gai Lead Actor

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    Maybe you can just order the circuit board?
     
  11. Girish

    Girish Stunt Coordinator

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    I talked to harman about the circuit board. The send they want me to send the unit. In other words they want my money!!!
     
  12. Chu Gai

    Chu Gai Lead Actor

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    Yes, but over a grand for the work? Ouch! What's the cost of the board?
     
  13. Girish

    Girish Stunt Coordinator

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    It a simple slide in circuit board. But the problem is they donot sell it.
     

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