Right channel silent until volume is turned up on Yamaha receiver

S

ShrimpDuck

Audiophyte
Hello!

I have been having an issue with my Yamaha RX-V573 receiver for some time now. It has developed a problem of the right channel playing little to no volume when the receiver is first turned on until the volume is turned up. My receiver is set to start at -50.0dB and at this level the left channel is very noticeably louder and it sounds as if the right is dead silent. As I turn the volume up to -20.0dB I can hear the sound shift back into the centre as the right channel starts playing at a normal volume now. After I have turned the receiver up, I am able to lower the volume back down to -50.0dB where both channels play at their appropriate volumes but if the content is very quiet or nothing is playing the right channel can cut out again and I have to turn the volume back up.

Now, I have done some trouble shooting myself to try and isolate the problem. I have switched the left and right speaker outputs and the problem still persists on the right output channel from the receiver so the speaker wire and the speakers aren't to blame. I am currently using optical as my source from a PC however I have used HDMI and AirPlay, all presenting the same issues. The issue is prevalent on both Zone A and Zone B of my receiver in the right channel of these. I have also blown out dust from inside the receiver with some compressed air and I desoldered and switched the relay from Zone A (RY203) with the relay from Zone B (RY202) as relays seem to be the culprit found on other posts however this did not fix the issue. The relays themselves are sealed so I am unable to clean the contacts out with de-oxit but seeing as they are completely sealed and this is a 2012 model it seems unlikely that they are to blame.

As a temporary fix, I am able to plug my right speaker into the Surround Right output of the receiver and put the receiver into 7 channel stereo mode (This is the DSP mode, not true 7 channel audio). This takes a stereo source and plays the same input on the surround channels. Interestingly this channel works perfectly and suffers no volume issues even though it is just a stereo source being duplicated onto the surround channels.

If anyone has any inklings or ideas about what the issue may be it would be greatly appreciated as this is a very befuddling issue!

Receiver: Yamaha Rx-V573
Speakers: Wharfedale Diamond 8.3
Source: Windows PC onboard soundcard via optical
 
ryanosaur

ryanosaur

Audioholic Overlord
Do you have any opportunity to borrow a friends receiver for a brief swap out... just to eliminate anything else in your signal chain? (Though that seems unlikely, and since you’ve already shown a willingness to open your box up and perform surgery... but I had to ask :))
My instinct is that it may just be time to upgrade. Lots of good deals on last years models right now.
 
S

ShrimpDuck

Audiophyte
Just tested the speakers out with my old Yamaha Gx-505 amp and it worked perfectly so the receiver is definitely the culprit.

Can't buy any recent stuff as I am on a fairly tight budget unfortunately.
 
lovinthehd

lovinthehd

Audioholic Jedi
Might try a soft reset and/or a full factory/microprocessor reset.....
 
TLS Guy

TLS Guy

Seriously, I have no life.
Thanks for the reply. Unfortunately it is a hardware issue as I have reset, updated etc. many times and still not resolved
I suspect the problem is on that right channel power amp board.

After all you have done, I do not think you will solve this problem without a signal generator and O-scope. It is hard to find service techs, now, and the time and labor might not be worth it.

Are you using all channels? If not, take a power amp board from a channel you are not using and replace that right power amp board with it.

You other option is to see if a unit like it comes up on eBay for parts or repair. It is unlikely all the power amps would be bad.

Otherwise as others have suggested it is new receiver time.
 
S

ShrimpDuck

Audiophyte
I suspect the problem is on that right channel power amp board.

After all you have done, I do not think you will solve this problem without a signal generator and O-scope. It is hard to find service techs, now, and the time and labor might not be worth it.

Are you using all channels? If not, take a power amp board from a channel you are not using and replace that right power amp board with it.

You other option is to see if a unit like it comes up on eBay for parts or repair. It is unlikely all the power amps would be bad.

Otherwise as others have suggested it is new receiver time.
Yes it does seem like it has to do specifically with the right channel amp as Zone B uses the same amp for the right channel as Zone A and both exhibit the same problems. What do you mean by transplanting the power amp board exactly? Are you referring to the large white components or the 3 pin black ones attached to the heat sink as per the image attached? I am quite new to amplifier internals so still learning my way around them!

I'm not using the surround back channels so I would be able to take them out just not sure which components exactly to de-solder. Thanks!

Edit: There are 7 of the large white components, presumably for each of the 7 channels and then 14 of the 3 pin black components attached to the same heat sink if that helps clear anything up.
Yamaha.jpg
 
TLS Guy

TLS Guy

Seriously, I have no life.
Yes it does seem like it has to do specifically with the right channel amp as Zone B uses the same amp for the right channel as Zone A and both exhibit the same problems. What do you mean by transplanting the power amp board exactly? Are you referring to the large white components or the 3 pin black ones attached to the heat sink as per the image attached? I am quite new to amplifier internals so still learning my way around them!

I'm not using the surround back channels so I would be able to take them out just not sure which components exactly to de-solder. Thanks!

Edit: There are 7 of the large white components, presumably for each of the 7 channels and then 14 of the 3 pin black components attached to the same heat sink if that helps clear anything up.View attachment 33509
I don't know that receiver and dislike the lot of them. But usually each channel board is on its own circuit board. If all the amps are on one board you will be out of luck.

Can you post a photograph of a total view of the inside? Usually there is a power supply, pre/amp processor board, HDMI board and a power amp board for each channel.
 
S

ShrimpDuck

Audiophyte
Unfortunately it seems to me that they are indeed all on the same, large board.

First picture shows the HDMI board, all of the outputs and inputs on the same board.
Second picture is initial power board from the mains
Third picture is the transformer and the front panel PCB
Fourth picture shows the main logic and amp board underneath the HDMI board and attached to the heatsink
Fifth picture shows the HDMI board removed and the main board. This board has all the amps connected to the heat sink as well as all the majority of inputs (RCA) and outputs (Binding posts) attached to it.
Final picture shows the circuit diagram for the whole PCB, and it seems as if every amp for every channel is on there.

So unless I am able to switch out those components near the heat sink into different channels I think I may be out of luck but I would be more than happy for you to correct me!

Also, if you dislike receivers what do you use as an alternative?
 

Attachments

B

Beave

Audioholic Chief
In most receivers, the amp channels are all on the same board. Nothing unusual there. I don't know of any receivers with separate power boards for each channel or separate amplifier boards for each channel.

Your problem sounds like a cold solder joint or a bad transistor. It would be fairly easy to diagnose with some test gear (oscilloscope) and schematics, but it could be hard to figure out without such resources.
 
B

Beave

Audioholic Chief
Yes it does seem like it has to do specifically with the right channel amp as Zone B uses the same amp for the right channel as Zone A and both exhibit the same problems. What do you mean by transplanting the power amp board exactly? Are you referring to the large white components or the 3 pin black ones attached to the heat sink as per the image attached? I am quite new to amplifier internals so still learning my way around them!

I'm not using the surround back channels so I would be able to take them out just not sure which components exactly to de-solder. Thanks!

Edit: There are 7 of the large white components, presumably for each of the 7 channels and then 14 of the 3 pin black components attached to the same heat sink if that helps clear anything up.View attachment 33509
The three-pin black components are transistors in the power amp section. They are bolted to the heatsink behind them.

The large white components are resistors in the power amp section that need to be large because they have a lot of current going through them (so they're much larger than the smaller resistors nearby).

This is the power amp section of your AVR - likely where the problem is, but hard to say for sure. Unfortunately, it's a single layer board with all the components being through-hole components with the soldering on the underside of the board. So you'd have to take out the board to see the bottom side to check for bad solder joints and/or to resolder.

Single layer boards are the norm for this section of an AVR.
 
S

ShrimpDuck

Audiophyte
In most receivers, the amp channels are all on the same board. Nothing unusual there. I don't know of any receivers with separate power boards for each channel or separate amplifier boards for each channel.

Your problem sounds like a cold solder joint or a bad transistor. It would be fairly easy to diagnose with some test gear (oscilloscope) and schematics, but it could be hard to figure out without such resources.
Unfortunately I don't own an oscilloscope. Could a multi meter be used in the same fashion? I had a quick look for cracked solder while replacing the relays and didn't see anything but it can't hurt to take another look and reflow important components.

Any ideas if a bad transistor would show visual damage or would it be all internal?

Edit: Your other post just came through. Thanks for clearing up what the transistors and resistors were, much appreciated. I'll take the board back out again soon, not too time consuming once you've done it a couple of times!

Would it be worth it to switch a transistor or resistor from another channel to the faulty one to try and replace the faulty part? I don't use the surround back channels so it wouldn't matter if they had a fault afterwards.
 
B

Beave

Audioholic Chief
It would be a lot harder to debug with a multi meter. You'd really want to play a sine wave test tone and trace it around the board with an oscilloscope.

It might be hard to see a bad solder joint. Obviously bad ones might be easy to spot, but if this is in fact a bad solder joint, it's partially working, so it won't necessarily be visibly obvious that it's bad.

Reflowing several components around the amps is worth a shot in the dark.

A bad transistor isn't necessarily visible either.
 
S

ShrimpDuck

Audiophyte
Ok thanks a lot for your help. I'll reflow a lot of the joints and then give swapping out the right channel transistor and maybe resistor out. Thanks again for enlightening me on the insides of my receiver. Cheers.
 
TLS Guy

TLS Guy

Seriously, I have no life.
Unfortunately it seems to me that they are indeed all on the same, large board.

First picture shows the HDMI board, all of the outputs and inputs on the same board.
Second picture is initial power board from the mains
Third picture is the transformer and the front panel PCB
Fourth picture shows the main logic and amp board underneath the HDMI board and attached to the heatsink
Fifth picture shows the HDMI board removed and the main board. This board has all the amps connected to the heat sink as well as all the majority of inputs (RCA) and outputs (Binding posts) attached to it.
Final picture shows the circuit diagram for the whole PCB, and it seems as if every amp for every channel is on there.

So unless I am able to switch out those components near the heat sink into different channels I think I may be out of luck but I would be more than happy for you to correct me!

Also, if you dislike receivers what do you use as an alternative?
Yes, all the amps are on one board.

Here is the service manual. The pertinent pages are 98, 99 and 100. There seem to be a lot of parts already unavailable according to that manual. You can not use a multimeter in place of a scope.

The only thing I could suggest is that you isolate the preamp board output from the right front preamp and switch it to an input of a channel you are not using. I don't know if you have the chops for that or not.

I'm not surprised it gave trouble and that receivers seem so often to have such a short life. Building like this is what I call thrown together.

I use pre pros and external amps. If not it is new receiver time.
 
S

ShrimpDuck

Audiophyte
Yes, all the amps are on one board.

Here is the service manual. The pertinent pages are 98, 99 and 100. There seem to be a lot of parts already unavailable according to that manual. You can not use a multimeter in place of a scope.

The only thing I could suggest is that you isolate the preamp board output from the right front preamp and switch it to an input of a channel you are not using. I don't know if you have the chops for that or not.

I'm not surprised it gave trouble and that receivers seem so often to have such a short life. Building like this is what I call thrown together.

I use pre pros and external amps. If not it is new receiver time.
Yeah I would have no clue how to go about that. No worries, thanks for your time hopefully replacing the transistors and reflowing some joints can fix this.
 
TLS Guy

TLS Guy

Seriously, I have no life.
Yeah I would have no clue how to go about that. No worries, thanks for your time hopefully replacing the transistors and reflowing some joints can fix this.
Do you know how to replace transistors? That is a learned skill set. Just for starters the heat of a soldering iron kills transistors and so you have to use heat sinks. Also you must properly use the thermal paste in reinstallation and get the insulation right.

One last piece of advice. Shot in the dark repairs are very seldom successful. Worse they often make matters worse.
 

Latest posts

newsletter

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top