Yamaha rx v373 - no power

[mmoore5553]

Re: Yamaha rx v373 - no power

I am still hunting this down but on IC131 the first leg shows 12 volts when i should have much lower. Anyone have any ideas. I have included schemetic to show all the voltage drops. I tried to look at the pwr_ry but confused on which ic is actually doing that job. i did test most of the IC's out and did a continuity on the legs and they checked out fine.

[rievax_60]

Re: Yamaha rx v373 - no power

I wouldnt worry about the regulator input voltage being high. The 3.3v output is the important thing.

[tibimakai]

Re: Yamaha rx v373 - no power

rievax, this one sounds pretty much the same as my Pioneer.
I'm still waiting on parts, for both receivers.
Did you test your final transistors for short?

[TNathe]

Re: Yamaha rx v373 - no power

I have a v371 that i beleive took a lightning strike. Just joined this board to learn something and hopefully fix my dead receiver. Mine was in your state, dead. No relay clicks or anything (unless i held down power, and the other 2 buttons to bypass protection mode). Then it would just click on/off

I replaced c1507 and c1502 last night. I now get the receiver to click on, then about 1 second later it clicks off. So i think i am making progress and it seems my receiver is in the same state as yours. I was going to try replacing the tranformer since i too saw very low resistAnce compared to the 6ohms that one vid said it should have. If i wanted to replace this transformer which one could i use? I cannot locate anything with the same part number.

[mmoore5553]

Re: Yamaha rx v373 - no power

Sorry wish I could give ya some insight but i went ahead and gave it to a friend. I wish you luck though.

[TNathe]

Re: Yamaha rx v373 - no power

Okay, picked me up a good book at the library today after work titled "How To Diagnose And Fix Everything Electronic". It was a great read for any of us beginners who want to learn what it takes to properly troubleshoot an issue.

I am hoping someone here can give me some direction here. I am tracing the circuit trying to determine where the fault lies.

SYMPTOM: Power on button causes relay SW151 to switch. About 1 second later the relay will switch back.

REPLACED SO FAR: Capacitor C1507

Here is the diagram:


From my understanding of this transformer, I should be able to test resistance across the "gap" of T1501 (BLUE ARROW). When I test this I get 0.F on the display of the MM. There should be pretty heavy resistance across these paths correct? This is being tested in-circuit btw.


Thanks guys.

[YAM373_DLN]

Re: Yamaha rx v373 - no power

@mmoore5553
I have the same defect in my receiver. Did you fix yours?
You are kind to me and send me the service manual?

Thank you.

[budm]

Re: Yamaha rx v373 - no power

[YAM373_DLN]

Re: Yamaha rx v373 - no power

I got this: "Error! This file not found! It may deleted or renamed."

[budm]

Re: Yamaha rx v373 - no power

I saw that now too, I hope other people in this thread will up load the service manual.

[YAM373_DLN]

Re: Yamaha rx v373 - no power

I hope too, so who has a service manual for Yamaha rx v373, please give me a link or something.
Thank you.

[tibimakai]

Re: Yamaha rx v373 - no power

Did you guys check that thermal fuse? It can be replaced, you don't need another transformer.
Also, from my little experience with these newer Yamaha receivers is, that the receiver needs to be reset to clear the error code(s).

[xsony30]

Re: Yamaha rx v373 - no power

mmoore5533, I have a RX-V373 with the same problem, no power, relay clicks on/off immediately. I found that 3.3vdc supply to IC225 pins 120 and 121 was shorted, causing it to go into protect. Holding down "INFO" AND "TONE CONTROL" while plugging in AC cord cause ac power relay to click. Still trying to find short, I really need diagram of the HDMI/CPU circuit board layout. Do you still have the schematics?

[mmoore5553]

Re: Yamaha rx v373 - no power

Sorry, I have search everyone for that manual and i do not have it anymore. I think that is when my laptop crashed. Sorry.

[mmoore5553]

Re: Yamaha rx v373 - no power

I found it. Sorry about everyone else asking about it. I never got an email saying this thread was updated.

[budm]

Re: Yamaha rx v373 - no power

Thanks!

[xsony30]

Re: Yamaha rx v373 - no power

Thanks for the service manual, mmoore5533. I found the short was in IC202, the HDMI receiver. I tried applying 3.3vdc to the circuit trace after removing Digital board from the unit and the HDMI IC started getting hot, drawing over 5A!

[xsony30]

Re: Yamaha rx v373 - no power

Unfortunately Yamaha has neither the CPU (IC225) or the HDMI IC202, so I am basically s.o. l.

[stj]

Re: Yamaha rx v373 - no power

so what's the part number for ic202?

[xsony30]

Re: Yamaha rx v373 - no power

It is a Silicon Image SiI9573CTUC, but there is no listing in the parts list. I would not look forward to changing a SMD 176-pin IC.