RX-V850, won't turn on

Discussion in 'Yamaha' started by Roboturner91, Jun 6, 2018.

  1. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    I've had this for about a year and have used it quite a bit, but never very loud.

    It started acting up the other day, after I powered it on, no speaker relay click, then it turned itself off. After a couple times it would kick on and stay on, but it took a while; what I've heard called a "lazy" relay. Today I couldn't get it to come on at all.

    The power cord got impaled by one of the spikes on my stand as I was moving the stand, but looked to only be superficial damage. I spliced in a new power cord hoping the fix would be that simple, but no dice.

    Is there any chance that it's the speaker relay itself? I don't see anything melted or burned inside, and like I said, when the relay clicked before it worked fine.
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

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    The relay click is your protect relay. Which means the protect circuit is detecting DC volts at the output of one of the power amplifiers. Or thinks it detected DC at the output.
     
  3. mbz

    mbz AK Subscriber Subscriber

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    The RX-V's are quite complex to troubleshoot, microprocessor controlled, multichannel...
    Best to check the diagnostic menu/protection history for some indication of why it's in protect.
    Could be something like excessive Vdc on spkrs or failed voltage regulator/psu cap...
    Will try and find diag procedure.
     
  4. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    This is an early Pro-Logic receiver, doesn't have a lot in common with the later models. I doubt the problem is related to any computer doo-dads but I guess I'll leave it in the hands of the fix-it place down the road.

    It's probably going to be more money/trouble than the thing is worth but I love the way it sounds and looks.
     
  5. mbz

    mbz AK Subscriber Subscriber

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    Could not find the RX-V850 sm. Working off the RX-V1050 (hifiengine), maybe it's the same???

    Appears to be an early version of the RX-V's, no protection history like the home theartre types
    Page 9 of the 1050 sm has a description of the protection function (Vdc, Over I and mute)
    Really need the RX-V850sm then confirm problem is due to excessive dc voltage.
     
  6. petehall347

    petehall347 the brandy coffee man Subscriber

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    i would try with nothing connected to unit first like speaker cables or inputs .
     
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  7. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    Ha, so I took the faceplate off this thing. Just digging a little deeper to rule out anything obvious, like gunk in the power switch, etc. On a lark, flipped it on and it works. It's been on nearly an hour now. I put the faceplate back on. Still working.

    I'll leave it on until morning just to make sure but it was shutting off within 3-4 seconds of power on before. Now it seems perfectly normal. Only thing I can figure it maybe one of the faceplate screws is also a ground connection and it got loose somehow, and when I took off the faceplate and reinstalled that fixed the issue.

    This stuff is weird sometimes. I was about to drop $225 plus shipping on a refurbished one because I fricking love this thing so much.

    Nostalgia is funny. I had a CA-810 for quite a while, and I liked it a lot - but I didn't grow up the late 70s. Something about this early 90s Yamaha gear just seems "right" to me.
     
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  8. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    So another update - I turned it on this morning and it turned back off after a couple seconds. Tried a couple more times, it finally clicked on and stayed on.

    Seems like there's no problem at all once I get it to finally 'turn over'. Reminds me of an old car that has problems with cold starts - or my weed eater for that matter.

    Maybe that behavior will mean something to somebody in terms of diagnosing the issue, IDK.
     
  9. audioman00

    audioman00 Well-Known Member

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    Bad solder joint?
     
  10. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    That makes sense to me, but my fix-it abilities are limited to sloppy soldering and spraying De-oxit. My diagnostic skills are zero, I have a multimeter but those numbers are all gibberish to me.

    I guess I could just leave it on all the time....haha
     
  11. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    My backup receiver (a Yammie RX-770) started doing the exact same thing today. Derp. Must be the power outlet. Wish I had thought of that before I fried another receiver. :(
     

     

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  12. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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  13. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    I think the RX-V870 is very similar if this helps as there is a service manual for this model. I think your RX-V850 is too early for the common fault of the mylar cap on the standby board.

    Unlikely you have shorted outputs if it has come out of protection on occasion, could be that one of the voltage regulators is faulty and causing shutdown.
     
  14. milo63

    milo63 AK Subscriber Subscriber

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    I've got a perfect RX-V870 that I can't give away, it sounds great and even has the remote.
    Best offer so far is $30.

    Can't keep them all..
     
  15. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    Are you sure your speaker wires or speakers themselves aren't causing this since it has happened on both receivers?
     
  16. petehall347

    petehall347 the brandy coffee man Subscriber

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    i have been wondering that since i suggested it earlier .
     

     

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  17. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    Sorry pete l didn't see you had already recommended this ;).
     
  18. Roboturner91

    Roboturner91 AK Subscriber Subscriber

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    As far as I can tell everything checks out. Visually inspected speaker wires for tears in the cover, tested for continuity, took the speakers apart and tested all the drivers. All OK.

    Now the crossovers are another issue - I don't know how to test those, but all the solder points all look good.

    I ran an extension cord to the other outlet in the room (there are only two) and the whole setup working fine. No signs of trouble. My computer has been plugged into this outlet for weeks so I can't imagine there would be a similar issue with it. Got an electrician coming next week to check everything out.

    This is why I wanted to buy a newer house. Of course I was overruled by my wife because she wanted a house with "character." Now I'm kinda stuck with it.
     
  19. petehall347

    petehall347 the brandy coffee man Subscriber

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    so its just the power outlet broken because maybe power cable being spiked or was simply waiting to break .
     
  20. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    Sounds like your speakers are fine, if the impedance tests the same on both they won't be a problem. Approx 6.5-7.2 ohms is common for an 8 ohm speaker.

    This is very interesting, please let us know what the electrician finds.
     

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