Not sure if this might be your answer, but worth a check perhaps...
Maybe check that the audio-out is not set within the TV settings to either DTS, nor Dolby Digital Plus, as those formats (that are supported by the TV) are not supported by the Sonos Beam. You need to set the output either to Dolby Digital (preferred) or the PCM codec.
It might be worth trying the optical out and the adapter, purely for troubleshooting purposes.
Not sure if this might be your answer, but worth a check perhaps...
Maybe check that the audio-out is not set within the TV settings to either DTS, nor Dolby Digital Plus, as those formats (that are supported by the TV) are not supported by the Sonos Beam. You need to set the output either to Dolby Digital (preferred) or the PCM codec.
Thanks for the advice, I did check and it was still set to PCM. Such a frustrating issue.
Thanks I have tried and the beam works with Optical all very confusing.
Tell a lie, thought I had the optical working turns out it wasn’t. So basically with ether option I can’t get the beam working with the T.V.
I have reset both the T.V. And the beam and still no luck. Do you think I should be taking them back to the suppliers?
Tell a lie, thought I had the optical working turns out it wasn’t. So basically with ether option I can’t get the beam working with the T.V.
I have reset both the T.V. And the beam and still no luck. Do you think I should be taking them back to the suppliers?
You set the sound out to PCM (stereo only) - I would try ‘Dolby Digital’ (not the plus version) .. if still no joy, I would at the very least speak with your TV manufacturers support desk to see what TV audio-out settings you need to put in place to send Dolby Digital to either your Arc or optical port - whichever one you are now using for your HT setup.
Thanks for your continued support. Today I spent a further 2 hours on this issues.
Firstly I plugged my PlayStation into the ARC HDMI and switched the T.V. On using my PlayStation control. I wanted to confirm that the ARC port on the T.V. Is still operational. Which I believe it to be.
I also did a full hard reset on the T.V. Inputted all my details into the T.V. Again.
I did a hard reset and re installed the beam. After this I went through the output settings once again.
maybe I’m missing something.
Firstly I selected “speakers” from the action menu and selected “Audio System”
Then into “settings” - “Display and Sound” - “Sound”
Then I have various options to choose from
ClearAudio+ on or off
Sound Mode “Standard”/“Dialogue”/“Cinema”/“music”/“Sport”
Sound customisation.
surround effect 1-6, Equaliser, voice zoom, Night on or off
Volume Level, Volume offset, Dolby dynamic range.
after that and from the settings menu I have “audio output”
Speakers - TV audio or Audio system (I have set to Audio system)
Headphone/Audio out - Headphone/Audio out (fixed)/Audio Out (variable)/Subwoofer
Headphone speaker link on or off
Audio system prioritisation/ output sound from Bravia Sync compatible external speakers if detected when the tv is powered on. On or off
Home theatre control turns your audio system on, and allows you to control it. When clicked lots of info displayed no options to click.
Sound mode sync - The sound field of the specified audio system will switch automatically when the T.V’s sound made changes on or off
digital audio out -
auto 1 output compressed without change
auto 2 output only compressed audio for multi-channel content without change
PCM Always output in PCM
digital audio out Volume min to max
that is all my audio options I have tried various options and non have enabled Sonos to find ARC I am totally bummed out with this now both the TV and speaker are premium makes and collectively have cost £1500.00 I wouldn’t expect this much hassle from ether.
Any further advise is gratefully received thanks 
I’m sorry to say, as another user here, I don’t know the workings of your particular Sony TV model, but most (not all) of the things you refer to in your post above appear to be related to the internal TV speakers sound-out.
A Sonos HT device is a fairly straightforward TV receiver/speaker and it will certainly play when it receives the correct audio-out from the TV - which will need to be either PCM stereo or Dolby Digital (not DD+ if using the Sonos Beam, nor DTS audio-out).
I think you are perhaps more likely to find a user on the Sony forum, or perhaps a person from the Sony Support desk who will be able to guide you to putting in place the correct TV settings needed to output Dolby audio to an attached receiver ... the Sonos HT device.
I’ve tried searching through other threads here for your TV model, but can’t see any other reports about it.
So you might ‘perhaps’ be better off speaking to those more-likely to know the answer to this, unless you just happen to find another Sony user here who has the same TV model Sony KD-75XG80xx.
If you do hopefully find the answer to this, then I also hope you will be kind enough to perhaps post it back here, to maybe assist any others who may have the same difficulty with their Sony TV audio-out settings.
I honestly wish I knew the answer for you.
Again thanks for a prompt response, when I get to the bottom of the issue I am having I will report back to save people’s time in the future. I wish you all the best Ken
