Oh, I found that chip. its in accessible to test with the amp still assembled.
That Connection 81 was the way to go.
Cool.
Srinath.
That Connection 81 was the way to go.
Cool.
Srinath.
Hi,
If you follow the signal path for the PRV it will take you to pin 65 to the MAIN CPU IC3 made by MICOM Part number HD54F3337YF15. It is the large IC in the middle of the page.
If you follow the signal path for the PRV it will take you to pin 65 to the MAIN CPU IC3 made by MICOM Part number HD54F3337YF15. It is the large IC in the middle of the page.
Pin 65 is connected to middle pin of #81.
2v dc flash at startup = bad I think, you said high, but what is bad - the IC ? or one of those power transistors ? I can desolder those 1 at a time ...
Cool.
Srinath.
2v dc flash at startup = bad I think, you said high, but what is bad - the IC ? or one of those power transistors ? I can desolder those 1 at a time ...
Cool.
Srinath.
Hi,
Q127 it is the negative driver transistor for the speaker channel A. That it is why the micro do not allow to power on to protect the speaker A.
Q127 it is the negative driver transistor for the speaker channel A. That it is why the micro do not allow to power on to protect the speaker A.
Hi,
I forget to explain that the signal PRV it is "AND" gate of all speaker outputs. Any one will indicate to the micro that there it is a problem with one of the channels.
I forget to explain that the signal PRV it is "AND" gate of all speaker outputs. Any one will indicate to the micro that there it is a problem with one of the channels.
So 2v dc at pin 65 on startup means its got an overload ?
Maybe Q127 is bad, I cant see it, I saw its solder side that was burnt looking.
Cool.
Srinath.
Maybe Q127 is bad, I cant see it, I saw its solder side that was burnt looking.
Cool.
Srinath.
Maybe try this, like mentioned earlier, the cap is a common fault.
EEVBlog #379 - Yamaha RX-V557 Receiver Fix - YouTube
EEVBlog #379 - Yamaha RX-V557 Receiver Fix - YouTube
c801 is the only one that seems to fit that description.
I'll pull it and check.
Thanks.
Srinath.
I'll pull it and check.
Thanks.
Srinath.
c801 showing 160K resistance. I think that's wrong. I think it should show a flash of resistance and open ... OK I'll find what goes in there and replace it.
Cool.
Srinath.
Cool.
Srinath.
You should measure the capacitance.
You fill up the cap when you measure resistance, once it's full it will measure infinite. ( zero when the cap is shorted out)
But it can damage your multimeter -> sends current back.
You fill up the cap when you measure resistance, once it's full it will measure infinite. ( zero when the cap is shorted out)
But it can damage your multimeter -> sends current back.
I dont have a capacitance setting in Harder fright issue multi meter.
OK I'll get some similar and put it in, its a smoothing cap isn't it.
Cool.
Srinath.
OK I'll get some similar and put it in, its a smoothing cap isn't it.
Cool.
Srinath.
The amplifier in the youtube video and yours are not the same. I'm not saying both amps had the same problem. There are several threads about Yamaha amplifiers with the cap problem on this forum.
Maybe there is some useful info there?
http://www.diyaudio.com/forums/power-supplies/213045-please-help-me-mend-power-supply-board.html
http://www.diyaudio.com/forums/solid-state/226279-yamaha-rx-v2600-does-not-power-up.html
Maybe there is some useful info there?
http://www.diyaudio.com/forums/power-supplies/213045-please-help-me-mend-power-supply-board.html
http://www.diyaudio.com/forums/solid-state/226279-yamaha-rx-v2600-does-not-power-up.html
Oooo I saw that 2600 thread as well, the cap I have to pull is the .01mfd 275. C805, not the one I pulled the 801. I gotta put it back in and get that other one.
Thanks, I'll get to it in a few days, we got polar front dumping rain/snow today and 2 days.
Cool.
Srinath.
Thanks, I'll get to it in a few days, we got polar front dumping rain/snow today and 2 days.
Cool.
Srinath.
I pulled that 275v cap. On mine its plastic body - looked like a mini version of that relay but grey in color. Its like 1/8th scale of that relay.
Can I replace it with a ceramic ?
Cool.
Srinath.
Can I replace it with a ceramic ?
Cool.
Srinath.
Polar vortex 2
He he ... atleast you can warm up (or cool down) with a nice doobie ... here I have to go all the way over to the west side of the country ...
We had a nice morning, its supposed to snow and rain and ice up later today. Beautiful 35 degree morning, perfect for me to fire up the irons and crack open the amp.
Anyway I have pulled the part. Now to find the replacement. This one also is showing continuity at something like 20k ohm. I think its leaking and letting in ripple ... which was what that RX-v557 guy said in that video.
Cool.
Srinath.
He he ... atleast you can warm up (or cool down) with a nice doobie ... here I have to go all the way over to the west side of the country ...
We had a nice morning, its supposed to snow and rain and ice up later today. Beautiful 35 degree morning, perfect for me to fire up the irons and crack open the amp.
Anyway I have pulled the part. Now to find the replacement. This one also is showing continuity at something like 20k ohm. I think its leaking and letting in ripple ... which was what that RX-v557 guy said in that video.
Cool.
Srinath.
25 Illinois Capacitor 01uF 275VAC 275V Polypropylene Type X2 Capacitors | eBay
That is what it looks like. Are those more prone to giving up ? I'd think the ceramic will be better than these ... I replaced a capacitor in my reel to reel a few years ago with one out of a fan that looked like that.
Cool.
Srinath.
That is what it looks like. Are those more prone to giving up ? I'd think the ceramic will be better than these ... I replaced a capacitor in my reel to reel a few years ago with one out of a fan that looked like that.
Cool.
Srinath.