Sony STR-DN1030 Distorted audio when Volume adjusted

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I didn't see the "vol" points... so you are probably right about that. To me, it is somewhat "different" for a selector to have volume control / gain in it. Perhaps, its just for muting / unmuting... maybe. Anyway, the suggested check may tell IF the signal is actually getting "inside" ic400 properly as those output pins, regardless of setting should see a "clean signal".

Further, since you know that only FL appears to be an issue, you can narrow some "poke testing" down to that in a few others area. As suggested earlier, in an unpowered/ disconnected unit state, you can do various checks with a meter... along with your eyes (ie. visual) looking for cracked joints / bad soldering. In the case of ic400, ensure that pins associated with FL are indeed connected "well". NOTE: in the page 32, that grounds for what appears to be ALL internals, seem to have seperate pins. Perhaps the ground for FL is not good (depending on the internals of the chip, it may have problems therein)... that can be checked by probe touching on the pin of the chip, not the solder point and referencing it back to some ground point elsewhere. This could tell you about the integrity of the pin contact point. Again, just an example.

Some other checks using a different "route". Input you test signal in the video audio input and look for the result in the rec output side of things (scope or otherwise).... is anything different?

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Ok, here is the scope capture video of the 75 (Channel 3) and 76 (channel 4) pins. Tapped into the C546 / C547 caps vs. actual pins - just for clarity.

DAC outputs seem good ? ? just sine wave, not volume controlled, probably as expected and no Jitter as you see on Pin 14 (Channel 2 of the scope) as volume adjusts up and down.

Anything else is needed to make a determination of what part of the circuit is bad?
https://www.dropbox.com/s/7u8kdole73...00926.mp4?dl=0

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

OK... I think that indicates that the input of your FLR is good and making it thru some portion of IC400. The 75/76 are fed to digital processing and then returned to IC400 for switching to outputs as necessary. That appears to indicate possibly an issue with ic400 on the FL channel output only. As suggested, check the video RL record channel output to see what's there.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

.... As suggested, check the video RL record channel output to see what's there ....

Not sure I'm clear on the ask here.

I think I've exhausted the resistance measurement and visual inspection - if something is wrong, I'm just not seeing it.

As to the IC400... BD3470KS2... Any idea if other replacement are out there? can't seem to find it. I see BD3471KS2 and seems pin compatible. .. but just wondering if anyone has had any experience with these.

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I am still thinking that your problem is associated with processing as opposed to the IC400. I was trying eliminate as many areas as possible.

Quote: "DAC outputs seem good ? ? just sine wave, not volume controlled, probably as expected and no Jitter as you see on Pin 14 (Channel 2 of the scope) as volume adjusts up and down. " You have looked at the DAC outputs?? The linked video isn't of outputs. Just a question to confirm things.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I am still thinking that your problem is associated with processing as opposed to the IC400. I was trying eliminate as many areas as possible.

Quote: "DAC outputs seem good ? ? just sine wave, not volume controlled, probably as expected and no Jitter as you see on Pin 14 (Channel 2 of the scope) as volume adjusts up and down. " You have looked at the DAC outputs?? The linked video isn't of outputs. Just a question to confirm things.

I've looked at pin 75 and 76.. they're labeled ADCRout, ADCLout... I know the sine waves are not "digital" output bad assumption on my part.. But I'm referring to pin 75 and 76.

Is there a conclusive test to figure out if it's processing? from reading your reasoning to looing at 75 and 76 you wanted to see what goes out to being processed is good. and it seems to be good (at least no jitter in amplitude or the Pin14 funny business) but you still think it's the processing that's bad?? trying to understand where processing / grounding / connection suspicions are coming from. Not to sound ungrateful but each of these tests to add wires, tap into resistors and pins requires disassembly and full assembly of the system and I think I'm getting close to using up max insertion rating on most connectors.

If there is something that you'd like me to do I'm happy to continue - but I'm not seeing why you think it's anything other than IC400 based on all the tests and findings

[CapLeaker]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Ok, here is the scope capture video of the 75 (Channel 3) and 76 (channel 4) pins. Tapped into the C546 / C547 caps vs. actual pins - just for clarity.

DAC outputs seem good ? ? just sine wave, not volume controlled, probably as expected and no Jitter as you see on Pin 14 (Channel 2 of the scope) as volume adjusts up and down.

Anything else is needed to make a determination of what part of the circuit is bad?
https://www.dropbox.com/s/7u8kdole73...00926.mp4?dl=0

would you please use the attachment feature (look for the paper clip on the very top). I hate having to use dropbox on my IPad, plus if not attached properly all the links you posted will be down after some point and the next one can't see them anymore.

[Per Hansson]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

CapLeaker: As is the videos are too big to upload, they can be converted in VLC to be smaller.
I did try and after conversion they are ok, but it would waste allot of server storage space if videos in such sizes where uploaded in many posts.
I don't disagree with your point at all, just trying to show the other side of the coin...

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

would you please use the attachment feature (look for the paper clip on the very top). I hate having to use dropbox on my IPad, plus if not attached properly all the links you posted will be down after some point and the next one can't see them anymore.

I attempted to upload! Max video aize allowed is too small for all conversion formats . All uploads resulted in failures. I will keep trying

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I've looked at pin 75 and 76.. they're labeled ADCRout, ADCLout... I know the sine waves are not "digital" output bad assumption on my part.. But I'm referring to pin 75 and 76.

Is there a conclusive test to figure out if it's processing? from reading your reasoning to looing at 75 and 76 you wanted to see what goes out to being processed is good. and it seems to be good (at least no jitter in amplitude or the Pin14 funny business) but you still think it's the processing that's bad?? trying to understand where processing / grounding / connection suspicions are coming from. Not to sound ungrateful but each of these tests to add wires, tap into resistors and pins requires disassembly and full assembly of the system and I think I'm getting close to using up max insertion rating on most connectors.

If there is something that you'd like me to do I'm happy to continue - but I'm not seeing why you think it's anything other than IC400 based on all the tests and findings

sorry for not being clear. The waves that you posted were for pins 75,76 which are the outputs of the IC400. They indicate that indeed the wave form coming in from the saccd input is making it "inside" ic400 and are being switched / connected to an output area... in this case, out towards the DSP processing boards.

IF those are processed ok, potentially they should come back in some form on pins 63,64. I don't know what those signals are like... digital (likely) or otherwise... but if they have issue, then potentially your problem is with the processing board and not with IC400.... remembering what I mentioned earlier about "straight thru"... depending on design / implementation, I do believe some designs still digitize a signal but don't do anything else (process frequencies / surround fields etc.

Anyway, it was some more checks as I usually try to exhaust as many alternatives before trying "major surgery" especially when dealing with meg pin IC's.

[CapLeaker]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I attempted to upload! Max video aize allowed is too small for all conversion formats . All uploads resulted in failures. I will keep trying

Maybe do some pics instead? It will suffice…
It's just a pain with Dropbox, I think even a YouTube clip would be better, if it really needs a video. I think that would make everyone happy, besides ending up in a dead link issue at some point.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

sorry for not being clear. The waves that you posted were for pins 75,76 which are the outputs of the IC400. They indicate that indeed the wave form coming in from the saccd input is making it "inside" ic400 and are being switched / connected to an output area... in this case, out towards the DSP processing boards.

IF those are processed ok, potentially they should come back in some form on pins 63,64. I don't know what those signals are like... digital (likely) or otherwise... but if they have issue, then potentially your problem is with the processing board and not with IC400.... remembering what I mentioned earlier about "straight thru"... depending on design / implementation, I do believe some designs still digitize a signal but don't do anything else (process frequencies / surround fields etc.

Anyway, it was some more checks as I usually try to exhaust as many alternatives before trying "major surgery" especially when dealing with meg pin IC's.

Thank you... i understand now. I will try to tap into those in the morning

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Reading back thru some replies, there is one other question.... are you using the same probe to read the same "bad side" all the time.... perhaps the probe is bad / has a poor contact internally (from my limited experience with my stuff, my probe's ground wire was "less than good" and it caused "funny" readings. Again, just a question to ensure things are what they are and not something else.

The reason that I ask this, is from what is being seen at points around ic400, there is no way that those would cause problems that you were "chasing" in the initial part of the thread especially, when you swapped devices and such. The "amplitude jitter" as shown is unlikely to cause protection operation. Of course, when you swapped the right for left, and still "heard" the problem, you didn't scope things at that point to see what the waveform was showing.... possibly "only amplitude jitter" maybe. IF so, then that would be "OK" as then the focus, where we are, would be appropriate. However, if the resulting output waveform of the swapped channel was significantly different, then there is other problems in the "back end" which need to be addressed. Not sure if that is clear but "internet troubleshooting" is tough as your hands / eyes aren't attached to my body... :-)

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Reading back thru some replies, there is one other question.... are you using the same probe to read the same "bad side" all the time.... perhaps the probe is bad / has a poor contact internally (from my limited experience with my stuff, my probe's ground wire was "less than good" and it caused "funny" readings. Again, just a question to ensure things are what they are and not something else.

Probe set is fairly new. Just to confirm I just swapped existing setup, and the amplitude jitter is there. It's audible with speakers and headphones and referred to it as a "Distortion" as I didn't know the waveform phenomena.

The reason that I ask this, is from what is being seen at points around ic400, there is no way that those would cause problems that you were "chasing" in the initial part of the thread especially, when you swapped devices and such. The "amplitude jitter" as shown is unlikely to cause protection operation. Of course, when you swapped the right for left, and still "heard" the problem, you didn't scope things at that point to see what the waveform was showing.... possibly "only amplitude jitter" maybe. IF so, then that would be "OK" as then the focus, where we are, would be appropriate. However, if the resulting output waveform of the swapped channel was significantly different, then there is other problems in the "back end" which need to be addressed. Not sure if that is clear but "internet troubleshooting" is tough as your hands / eyes aren't attached to my body... :-)

Recall the 2 main BJTs and 1 resistor were initially blown. I would guess amplitude jitter problem has always been there also. Once the BJTs and resistor were replaced, then the FL channel was operational and the amplitude jitter became a problem (as FL was dead before so no way to know)
The protection faults that occurred had to do with the chassis assembly. I was being lazy and if you assembly without many of the screws in the back tightened, you'll get protection fault. Protection fault, therefore is operator error from what I can see now.

Finally, all the last several probes have been done with pin 14 isolated from the amplifier stage (cap C710 removed)

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Ok,
So hopefully this takes care of things:

People preferred images rather than video so I'm attaching an image. Still amplitude jitter is occurring on pin 14 of IC400

Channel 1 input (large amplitude second from the bottom)
Channel 2 Pin 14 of IC400. Still shows amplitude jitter

Channels 3 and 4 are pins 63 and 64 of IC400 (DAC input - looped back from processing section)


So we looked at signal in, out to processing, back from processing, isolate IC400 from amp, and the issue seems to be in FLOUT (pin 14 of IC400)

Can we now say the issue is with IC400?

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I would say you have done everything possible to rule out anything which leaves only IC400 left channel output. Hopefully, someone else will tell you about your question about possible substitutes. Hopefully you are good at soldering / hot air work.

Having said, that have you checked your channel level settings to see how they are set? ... leave no stone unturned. :-)
Somewhat related, does this unit have built in test tones?

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

I am ok with soldering. As for the channel levels i am not sure what you mean? I never really used the unit, so i have to hit the manual.

Yes the IC400 IS BD3470KS2... not available anywhere it seems. BD3471KS2 seems to be pin compatible and is available in China any help is very much appreciated. Thanks again for all the guidance! It's awesome to have experts like you here!

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

On channel levels, most multi-speaker systems having settings for each channel level so that you can balance the "sound field" properly for any given system volume... so you use a sound meter or otherwise (phone app) to adjust the "trim" for each channel such that for a given volume at a given listen position, the sound coming from each is at the "appropriate level". Normal an internal test tone (white noise) is provided and can be switched to one channel at a time and levels are adjusted to "balance" things out. Not sure if this unit has this but most do have some form.

One other option to try with your problem is heating. IF you have a hot air soldering work station (or hot air blower), you can try heating the ic400 CAREFULLY to see if the characteristics of the problem change... ie. maybe it starts working well or totally stops while heated. This might indicate some form of thermal issue somewhere. Again, just throwing out some ideas of testing.

As far as the IC, not knowing anything but what is spec'd...IF at "face value", it looks the same (all pins) and the cost is cheap and your skills are OK, then it might worth a gamble to go for it... which are probably going to do ... right. :-)

[CapLeaker]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

As a last ditch effort, you can heat with wifeys hair dryer or freeze the IC400 taking a can of air upside down. Other than that, I’d be giving up and either replace the IC on the board. You did pretty darn good coming this far!

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

As a last ditch effort, you can heat with wifeys hair dryer or freeze the IC400 taking a can of air upside down. Other than that, I'd be giving up and either replace the IC on the board. You did pretty darn good coming this far!

Thank you very much!