Have you looked in the user manual: https://www.sonos.com/en-us/guides/era100

Yes.

There should be “Line-in” listed on the home screen in “Your Sources” . if its not there, try resetting the app or restarting your phone. The other way is to tap the gear icon in the upper right of the home screen and select the Era 100. On that page you will see all the selections for the Line-in.

https://support.sonos.com/en-gb/article/play-line-in-on-your-era-100

Ok I’ll try. brb.

Are you using the Sonos Line-in or Combo adapter?

Line in to C adapter

Is it the original Sonos adapter or aftermarket?

Check for updates to make sure you are running on the latest firmware.

Original. I bought them together.
Its works on Bluetooth but not line in. If theres no delay then perfect but I think BT will be delayed a tad.

Check for updates.

The official Sonos adapter?

edit: ignore, answered above

The one on the website thats $19

Have you checked the PC’s sound settings?

Yes it works via BT but the line out is blanked out in the app.

That indicates it’s not receiving a sound signal.  I suggest that you check the sound settings on your PC and double check the seating of the cable.

Do you have another device that could act as a temporary line in source to test?

You have the Sonos Line-In adapter connected directly to the Era 100?

Sadly no. I’m lost. Support told me I bought something thats not supported.

In your opening post, you mention line-in to your PC … just to clarify, you need an analog audio line-out, that’s usually either a 3.5mm line-out, or an RCA (left/right) line-out to a 3.5mm male connection, which in turn links to the ‘Sonos audio adapter’ and then its USB-C connects into the port on the rear of the Era-100. At that point you should see the line-in settings in the Sonos App become available for you to adjust/play/Autoplay the audio out from your PC’s sound card.

Yup….. No idea why its not showing up. Tried everything.

Maybe try a completely different audio source - a mobile phone/tablet, MP3 player, CD player, BT transmitter, Turntable, echo dot, or even audio out from a TV etc. just to rule out the adapter/cables/speaker perhaps being at fault.

If you just connect the Sonos Line-In adapter to the Era 100, the Line-In settings should be available in the app, even without the adapter being connected to any source. Then you just have to figure out how to get the sound from your PC.

Pics of your attempted connections may help.

Have you tried opening a CMD window on your PC and running dxdiag to check for sound output issues?

• The others work as normal. The Sonos does not.

• Pics of what? Ok so the mother board has a 3.5 from it too the Sonos which is then connected to the C adapter.
• Then I use the C & 3.5 to the mother board….. Same result. Nothing.
• CMD does nothing with the dxdiag. Thats info only and the Era100 is default.
  
  Below is the info from Sonos with regard to the Ray Soundbar. I got the same reply about the Era100.
  
  
  
  Hi Callum,
  
  Please don’t tell me that would work!! I sent my Ray back because when I was on live chat to Sonos I was told it wouldn’t work with a Creative Labs sound card. If that’s true I’m gutted as I have now ordered the Era 100 with USB-C to 3.5 mm Headphone Jack.
  
  Graeme.
  
  On 2024-12-20 12:29, Sales EU wrote:

  Hello Graeme,
  
  Thank you for contacting Sonos. Sadly Sonos are not easy to use as PC
  speakers unless you have a specific setup already.
  
  The Ray is actually a good choice if you can get your PC to work with
  it so if yours lacks a TOSLINK optical port that the Ray uses I would
  suggest to look into acquiring TOSLINK optical output PCI-E sound
  card.
  
  Its rather old school to make use of expansion cards on PCs these days
  outside of GPUs but a soundcard that supports an optical out would be
  what to use to make this function.
  
  I hope this helps!
  
  Kind Regards,
  
  ______
  Calum
  Sonos | Sales Experience Team

Sorry but your reply here makes no sense to me - what do you mean the others work as normal, but Sonos does not… Do you mean the PC doesn’t work, but all other devices play to your Sonos speaker?

My other sound outputs. Headphones, Headset & old speakers.

PC is Win11, 12th Gen i9 129000k, 64gb 3600, 4090GPU, 2x 1TB SSDs