And presented in Dave's unique non-scripted overly enthusiastic style!
The fix for the Yamaha RX-V557 Receiver.
A followup from the previous video:
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
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.
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.
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.
Sing some more!
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”.
Just done this trick on a rvx1600, an EBAY special spares or repair, replaced 22nF with 33 nF and powers up straight off now cool, thanks guys
Hey Dave, I was looking for an answer as to why my Yamaha HTR-5860 kept turning of on me after it being on for a few hours…. I came upon your YouTube video on my PS3 and enjoyed how you broke it down in laymen’s terms for me to understand. Now, the one you fixed in the video is 223k 630 volts. My Yamaha’s is a 473k 400volts… Would it be a wrong decision to replace mine with a 223k 630 volts???? I am a new hobbyist, so please bear with me. Please help me mate. Or should I buy the same one, 473k 400 volts??? Your reply would be greatly appreciated. I am going to donate to your blog by money order only, as I do not have a credit card. Pleas send instructions on how I can send this to you mate. Thanks a million
Hey Dave… I have a Yamaha HTR-5860 which turns off after a few hours of playing, and since I hear you say that the c405 is a common problem on these receivers,I would like to ask you this question. The receiver you fixed has a 223k 630 volts capacitor, my Yamaha has a 473k 400 volts capacitor. Would it be wise to change mu 473k 400 volts for the 223k 630 volts. Would it be a bad choice??? I don’t want to fry my receiver mate. I am new to this, and would like to hear a pro’s opinion on this matter. I would also like yo donate to your blog but can only do it through postal money order. Send me instructions on how to get it to your hands mate. Also, can you send me a link or the actual service manual schematic as an attachment in your email reply? Thanks mate. Looking forward to your reply. God Bless You.