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Just bought a Beam & LG C8 TV, so far they are both working beautifully with the exception of the loud noise I'm getting once I turn the TV off. It's very inconsistent, sometimes it happens 10 - 60 seconds after the TV is turned off other times not at all. I'm connecting the beam through the HDMI ARC port and using the supplied HDMI cable provided by Sonos. This doesn't happen with the built in TV speakers. Anyone experiencing anything similar?
Just bought a Beam & LG C8 TV, so far they are both working beautifully with the exception of the loud noise I'm getting once I turn the TV off. It's very inconsistent, sometimes it happens 10 - 60 seconds after the TV is turned off other times not at all. I'm connecting the beam through the HDMI ARC port and using the supplied HDMI cable provided by Sonos. This doesn't happen with the built in TV speakers. Anyone experiencing anything similar?



HI adodero,



Welcome to the community. Can you submit a diagnostic report after this happens, then reply here with the confirmation number?
I also have this intermittent issue.
My diagnostic number is 1116500253.
Thanks! I actually think I found a solution (so far no buzzing). Under General->Simplink(HDMI-CEC) TURN OFF (Auto Power Sync). This doesn’t need to be on since the Sonos never really turns off, this signal is essential doing nothing.
I’ll have a look through settings on the TV and see how mine is fixed. Thanks for the suggestion.
I think that's the first time I've seen a solution posted for that issue. Thank you!
Thanks guys. That was a setting I needed to change so will wait and see if I don’t experience that again. Cheers
Same problem here
Same problem here. Also with an LG C8. Doesn’t happen very often though.
Same issue. Tried the reommendation re turning of power synch but still happening.
Yes I have this too, a few seconds after turning the TV off I get a loud sudden buzz for a couple of seconds from the Beam. My TV is a LG SK8500. I have tried turning off the auto sync power setting but it makes no difference.
I get this every now and again. I have had my Beam for about a month and it has happened maybe 3 or 4 times. I have the beam connected via HDMI ARC to a brand new LG B8.
My Beam does the same hooked up to an LG E8 does the same Mr Sonos, heard it tonight and wife said it's done it a few times now. Tried the Simplex fix will wait and see if that works.
I have this issue with LG C8 — it can be VERY loud, the people living above me love to complain about noise. I need a solution.
I have this issue with LG C8 — it can be VERY loud, the people living above me love to complain about noise. I need a solution. LOL mine went off a couple of nights ago about 5 mins after I went to bed. It's only intermittent and seems quite random.
This sound is frightening. I just got a beam with 5.1 and LGOLED B8. My kid turned off the tv and it scared us. Is this on the agenda to be fixed? I haven’t tried the suggestion yet but it sounds like it doesn’t work for everyone and may be sporadic?
You may want to check with LG. From the other posts about this issue, it appears to be an extra signal being sent by the TV to the Sonos, and not something generated by the Sonos on its own.
Back to report the suggested fix does not work. This sound is extremely loud and happens once the TV is turned off. Is there a fix coming for this? There’s no way this is LG’s issue as I have another LG with a playbar and it’s never happened. It’s the Beam. Please Sonos release an update to address this it’s Soooo loud and scary like something is severely broken with the Beam
Same here, with LG C8 (firmware 4.10.55) Harmony One and Sonos Beam. Happens after turning TV off, sometimes 5 seconds after, sometimes 15 minutes after, randomly and infrequently (twice last week).

Suggested fix above does not solve the issue, but seems to have made it much less frequent.
Same issue I have had my Beam and & LG tv for 6 months and it has happened three times. After you turn off the tv a few mins later a very loud noise!
mine just buzzed too, diagnostic report: 1413397937
Same issue with LG tv

when I turn off tv after watch Netflix(in tv app), this issue will happen
Note that in all of the resolved cases of this issue, it has been the TV sending an errant signal to the Sonos.



There are are unresolved issues as well, but so far, there’s been no indication that it is a Sonos issue in terms of either their hardware or software.
I have the same issue with my LG C8 hooked up to a Sonos AMP. It’s happening at random.
I had the same problem, I fixed my buzz noise by turning off the power down beep or tone associated with turning off my LG TV. since I did that no more buzzing has occurred . The quick reply from Sonos help made me think about the power down beep as they mentioned that some audio data was still being received when turning off TV. Hope this helps