Sony STR-DN1030 Distorted audio when Volume adjusted

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Thank you so much!

[CapLeaker]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

A1! Congrats!

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

that's great. Glad it worked out with a replacement. Good work and learning.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Ok.. Just received the IC.. Installed, all went well, almost
The chip works, none of the distortion is audible (no scope captures - I think I've had enough )

I think I may have lost a pad because I lost "Video 2" source, but other than that, everything is working well. Still haven't tested video and other sources, but at least the initial goal of repairing the "Distortion" is a success.!!!

Thank you all

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

BD3471KS2 seems to be pin-compatible. Rohm is not much of a help. So it's a chance.

I don't have a datasheet for the original part BD3470KS2, except the schematic sheet in the manual for the amplifier.

[CapLeaker]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Unfortunately, IC400 has been removed off the board. The good news, it was removed successfully. Awaiting a replacent

Did you find a compatible match or a replacement ic?

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

that's ok... hopefully the replacement will indeed solve the problem. Hope the "slow boat" moves faster. I too am waiting for stuff to cross the ocean. :-)

One thing that you might consider is doing a "quick" comparison measurement of the FL/R pins on the new and old chips since they will be demounted which might give you some confirmation that the problem was indeed associated internally with those channels... maybe.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

Unfortunately, IC400 has been removed off the board. The good news, it was removed successfully. Awaiting a replacent

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

sorry if this "horse has been beaten to death"... I still get the feeling that there is a connection problem somewhere.... possibly a lost / poor ground on the channel. In your video, there is "5" waves on your display from 4 probes. From limited experience, it almost appears to be like a trigger problem. The other thing that seems "interesting" is the wave form is almost 180 degree out of phase which seems strange but maybe plausible although the other DAC output wavesforms have gone thru some processing and don't seem to have any "shift". Refreshing the ground points on the IC might be useful.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

well... not fun. It was just a thought. Having said that, you will need practice removing / getting access to the ic to change it out. You might want to practice "one time" and try a "reflow" of the ic / pins... with flux and soldering... just for "fun". Again, if your time isn't critical. Good luck, and great effort.

Thank you so much again!

So here are the videos with BoxDrop links earlier in the thread, very shrunk with removed audio. Let's hope they upload

[budwich]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

well... not fun. It was just a thought. Having said that, you will need practice removing / getting access to the ic to change it out. You might want to practice "one time" and try a "reflow" of the ic / pins... with flux and soldering... just for "fun". Again, if your time isn't critical. Good luck, and great effort.

[jason123]

Re: Sony STR-DN1030 Distorted audio when Volume adjusted

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. :-)

I went for it. BD3471KS2 seems to be pin compatible and available from Aliexpress... will be a month before it gets here but i will keep you posted!

As for heating / freezing the IC, It's on the bottom side of the main board. I cant get the system to operate out of the casing. Tried to heat up through the venting holes on the bottom of the chassis, but not sure how hot the IC got, especially that i cant see it!

Thanks again..

[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!

[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!

[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. :-)

[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

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

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?

[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)

[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... :-)