No audio from Sonos Port digital output - "PCM Zero" signal.

  • 29 March 2023
  • 48 replies

Userlevel 2
Badge +2

Hi Folks, my Sonos Port is plugged in to a Lyngdorf amplifier via digital coax and has worked fine since I set it up initially. However, I’m not hearing any sound from the Port now, and the amp says it’s receiving a “PCM Zero” signal - it was fine on Sunday but no sound from any source on via the Port now. Has an update changed something? Any help would be hugely appreciated, thanks!

Corry P 5 months ago

Hi @only_sleeping et al

We now consider this issue fully resolved. If anyone is still experiencing problems, I recommend they get in touch with our technical support team. 

Thank you for your patience.

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48 replies

Userlevel 2

I have the same problem, but with Genelec 8340 active speakers. Hopefully there will be a fix soon.

I’m not aware of any change in the update that would factor in to this. Have you tried to submit a system diagnostic , and called Sonos Support to discuss it?

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network. 

I also have the same problem but with an Arcam SA20. Amp shows 44.1kHz signal received but it’s totally silent. This worked fine for a year until a couple days ago. I also noticed my system did an update so I expect the update broke this. I tried contacting support, they said my Port is out of warranty and I need to buy a new one. Not helpful. I actually have more than one Port. They all exhibit this sudden behavior change. I wish we could somehow report this bug to the actual engineers.

Userlevel 2
Badge +2

Thanks for the replies so far, they are useful if only to confirm that I’m not the only one with the issue and that the unit has updated and Sonos have caused the issue. 

I chatted with support last night who refused to help any further until I contacted Lyngdorf to ask what “PCM ZERO” meant! The replies from other posters this morning seem to confirm that this is an issue caused by a Sonos update though, the second time in recent memory that an update has broken some functionality with the system for me (which I find really hard to forgive). 

I’ll wait to hear back from Lyngdorf and then contact support, but in the meantime, if anyone else learns anything new, please share. 

Same problem here. I have a pair of Dynaudio Xeo 4 and have used the coax-output for years without any problems. Stopped working yesterday. Hopefully a fix soon…

I’m having the same issue with my Port + Genelec 8330A/7350A system. This is most certainly an artifact of the recent update, as I also had this issue with the beta. 

Userlevel 1

Same problem with me!   Arcam SA30 amp which was working fine now says the digital input from the Port is ‘Not Valid’.   So frustrating!

I have the same issue. My Port is connected to NAD 3020 and it stopped receiving digital signal from Sonos today. Worked fine last time. Analog output works properly. I thought my coax input or output blew up, but apparently not.


Any word on a fix? 

Userlevel 2
Badge +2

I’m chatting with support. 


They are aware of the issue and working on a fix, but refusing to blame the update or provide any kind of timeframe.

Exactly the same here. I was worried, I thought it might be my active speakers. Glad I found this topic. Hopefully there will be a fix soon. 

Same here. Port connected to a Cambridge DAC Magic100. Tested both S/P DIF input ports available on the DAC. Both signal 44.1 input but stay silent.

I work for an audio store and we are Sonos dealers experiencing the same problems with out demo ports. It’s unreal to me that they would release an update that cooked the Digital out. I’ve tried our Port on the Parasound Hint 6, Arcam DACir-II, and the Rega Saturn CD Player DAC, and none of them work. It is completely unreal!

Have you provided any data to Sonos about it? While it’s mildly helpful to share your shock with this community, it might go a lot further if you were to share hard data with Sonos, so the engineers might address this issue more speedily. 

Same problem here, since last update the digital output isn’t working… how long doesn’t it take to release a rollback? 
we have clients asking to get rid of Sonos already… this is unacceptable. 

We have a bunch of clients with Port’s that have broken DIGITAL OUT since the last update… Thanks sonos! 

Userlevel 7
Badge +15

Hi @only_sleeping and all,

Our engineers are aware of this issue and are currently investigating as a priority while working towards a fix, however we do not have an estimate on when this will be resolved to share at this time.

In this case, the analog output will still work and we would recommend using this if possible.

If the analog output isn’t working, then you may be experiencing a different issue and I would recommend reaching out to our support team.

I hope this information helps!

Userlevel 2
Badge +2

Whilst I appreciate Sonos acknowledging the issue on the forum, it’s worth noting a lack of an apology or admission that the update has caused the issue. 

How does a mistake like this happen?

Why haven’t they rolled back the update?

What compensation are they willing to offer customers whose devices they have (hopefully temporarily) crippled?

Userlevel 3
Badge +5

It can also be added, when you use the analogue output and quickly operate the balance control, the bass and treble sliders changes randomly.


Same problem with Genelec 8341!!!


emabarrassing SONOS…



Same issue. Just installed a new Port yesterday.  RCA analog works but zero sound via the digital coax connection. Note the port completed an update yesterday as well.


Same issue here as well.

Appeared somewhere between Sunday March 26th and Wednesday March 29th.

Maybe linked to the launch of the Era 100 & 300 and updates with Dolby Atmos audio support.

I cannot check if analog audio works since the Port is hooked to a Bel Canto DAC 3 and it only has digital inputs.

In any case, the only use for the Port is to connect to the Bel Canto DAC in my listening room.

Sonos should know the customers that has a or some Ports.

They could send these owners an email to warn them and not start messing around with changing and testing digital coax cables like I did before finding this on the forum.

Same here! (Port with Lyngdorf)
And yes, I messed around with cables and other digital coax sources to find out 'what has been broken’. Please SONOS, warn owners and users when this is a known issue

I spent over an hour with a Sonos tech rep on this problem -- I had just purchased a new Sonos Port, and I was getting no sound on my Denon receiver -- and the tech didn’t know of the bug until he checked with his supervisor because we were getting nowhere. Total waste of my time. It is extremely frustrating to buy this new device, have it simply not work, and then have the company rep not know of the cause, then finding the cause and having no estimate of when it will be fixed. So essentially, I’ve just spent  >$400 for a useless brick. 


Having same issue. System has been working find for years, not working now. Where to look for update? Going to analog out is not an option for me, Sonance DSP amp with digital input card only.