8 responses to “EEVBlog #379 – Yamaha RX-V557 Receiver Fix”

• Bob Saget 4 lyfe October 31st, 2012 at 21:00

  Hey Dave, looks like the download link on this one is incorrectly pointing to the last episode’s url. Also a big thanks for offering direct downloads rather than YouTube :3

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  • EEVblog October 31st, 2012 at 23:20

    oops, fixed.

    Reply

• Manwolf November 1st, 2012 at 06:23

  As a guy who works on mains level voltages more than low voltage, I chuckle when I hear all of the warnings. I get the jitters when working on low voltage, all those shiney exposed places to short out LOL. Great video glad to see you got it going again.

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• Ratib November 1st, 2012 at 07:50

  The capacitor is shorted! It is shorted between the foils, probably due to a high voltage spike. The spike will burn through the polyester film and leave a carbon trace. If it is only shorted through a few turns it will read as low capacitance.

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• ph_001 November 1st, 2012 at 20:02

  It seems that the failed capacitor still provided enough current to keep the power supply going, but not enough to switch IC401 on. This optocoupler obviously generates some “power good” (or reset) signal. So the micro most likely was just held in reset.

  PS: This obviously isn’t a “real” (high frequency) switch mode power supply, but rather a mains transformer that gets switched on when needed – on mains cycle by mains cycle basis. That is, it is switched on while the output voltage is below nominal and is inhibited via IC403 when the output voltage is high enough.

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• Mike November 1st, 2012 at 23:42

  Sing some more!

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• Odo November 3rd, 2012 at 02:44

  I love when I learn new Aussie expressions on the eevblog.

  “Stick out like a pair of dog’s balls”.

  Also: 500pF: “Five hundred poof”.

  Reply

  • EEVblog November 4th, 2012 at 19:20

    “puff”!

    Reply