Anyone ever lose a Preamp channel?

Discussion in 'AV Receivers' started by Grant B, Jun 20, 2005.

  1. Grant B

    Grant B Producer

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    After spending a good part of weekend behind my rack troubleshooting it seems like I have nothing coming out of my preamp Right surround output.
    I have lost amp channels before but never a low level output in 20 years and find it strange.....I spent so much time looking for a amp problem I overlooked that possibility so I didn't find it till sunday night.
    By that time I was a little frazzled to say the least.
    It's a Sony TAE 9000ES pramp that has never had a problem and of course it's 5 year warranty just ended.
    I checked the service manual and it doesn't look like individual channel outputs are fused and I tried the 15 minute unplugged factory reset trick..... anyone have any ideas before I go home and unwire it and take it in for servicing?
    Just trying to get a sanity check here since I question my own after way to many hours working on it.
    Thanks
    Grant
     
  2. John S

    John S Producer

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    I have had pre/amp channels go. The most common is the pre out channel gets loosend by plugging and unplugging stuff into it and has to be re-soldered.
     
  3. Grant B

    Grant B Producer

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    John S
    That sounds very likely, thanks!
    Did you ever attempt to fix one yourself yourself?. Seems fairly a 'straight ahead' problem....continuity from the connector back and re-soldered the open.
    The only variable I see is how buried under boards etc.
     
  4. John S

    John S Producer

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    yes.. This is easy.. Usually a one shot ith the iron with some solder fixes it right up.


    The long part is getting the board so it can be soldered on....


    While your in there, ya may as well hit each output with the iron and some solder. You will be shocked at how little solder they actually use on these connections.
     
  5. Jesse Sharrow

    Jesse Sharrow Supporting Actor

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    I would do as john said and try to fix it yourself. Since its out of warrenty they may charge you to fix it anyways. But I would think with a 5 year warrenty they may be understanding. So just try not to make it look like you tried to fix it yourself. Also you may want to call sony to see if they will fix it. Then make a desicion.
     
  6. Grant B

    Grant B Producer

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    Thanks
    My trusty ohm meter should tell me pretty quick if it's a solder joint; if it's not I'll take it in.
    Generally it's not the money but the turnaround time and inconvience of a big hole in my rack for a week or more.
    Looks like my Monday Night is booked up
     
  7. Grant B

    Grant B Producer

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    I have to admit that it wins the award for "Most tiny screws in a metal box"

    Unlike most units which have a big box and a small board this sucker is packed, luckily the analog board was accessable.
    Will hook it up ands try tonight......if you hear a scream; well don't come round
     
  8. Jesse Sharrow

    Jesse Sharrow Supporting Actor

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    I hope everything works out. Let us know.
     
  9. John S

    John S Producer

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    No Grant B post this morning?? I sure hope it all worked out.. [​IMG]
     
  10. Grant B

    Grant B Producer

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    Moving kind of slow this morning. Still a 4.1 system but hey we tried. I thought that might be the case when I was getting continuity from the connector to circuit board but was hoping it was a case of DMM probes causing it by pressure. My wife said she would drop it off at the repair shop.....they usually are pretty quick about it unless it's some strange part they need to order.
    I'll post the problem when I get it back

    Thanks everyone!
    I thought we had it there. Funny how this happens when 2 of my friends were in town and I was going to demo some SACDs for them....oh well
     
  11. John S

    John S Producer

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    Bummer. I actually thought we had it as well...

    Well it does happen. I had it happen on my previous AVR, channel would not work using the internal amps or the channel pre-amp out....

    I replaced the unit with my current Denon 4802.
     
  12. Grant B

    Grant B Producer

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    John
    One thing that occured to me while taking it apart, it's built like a brick #$%^&house. The connectors on the back were very tight with very little play. I have seen many others that secured a whole bank with only one or two screws.....not the case here.
    I just picked up a TAP 9000ES preamp to give me SACD 6CH Input.
    The TAE preamp hooks into the TAP and is an extremely silent pass through when off or in bypass mode. The only negative is more cables and it complicates troubleshooting when anything happens.
    Hows the Denon working out?
    I am confused on why the internal amp didn't work when the RCA connector was bad? Wouldn't the internal amp bypass the preamp out?
    Anyways Thanks Again
    Grant
     
  13. John S

    John S Producer

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    On that one.. It was also not the RCA connection.. I never trouble shot it beyond that, I just replaced it. But it did have pre-out to main-in jumpers, so I thought for sure it was the jack itself. I also re-soldered and nadda on it. Older Pioneer AVR....

    The Denon 48xx series is pretty impressive, It has been and is a joy to use in all honesty. The upgrade bug has sort of hit me again. I am working to true bi-amp all 7 channels these days.

    Takes a ton of time though, to really analyze everything making sure it all remains flat. I also have a new sub on the way.
     
  14. Grant B

    Grant B Producer

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    Yes I have run some frequency sweeps and it is very difficult. I was suprised to hear the pipes rattle though
     
  15. Grant B

    Grant B Producer

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    The shop just called and said nothing needed replacing it just needed recalibration which I find strange but it's under $100 and will be ready on Monday so I can't complain. Since I got rid of my O'scope many years ago I don't feel bad since I don't have the right equipment to fix.
    Thanks everyone for the reponses and help
    Grant
     

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