Espero que ajude:
The TV does not output sound through the DIGITAL AUDIO (OPTICAL) OUT jack.
If the TV does not output sound through the DIGITAL AUDIO (OPTICAL) OUT jack, check the following possible causes:
The connected home theater system, audio receiver or sound bar is not set to properly decode the digital signal.The TV is not set to a digital channel.The optical cable is not securely connected.The optical cable may be faulty.The TV may require a system software (firmware) update. Software and driver updates for your Sony product are available online.The connected third party sound bar or home theater system may not be compatible with the TV.For KDL-xxR550C models, the Digital Audio Out setting is not set to PCM.
IMPORTANT: The optical jack is designed to output sound when the content you are watching contains digital audio (PCM or Dolby Digital[emoji768] technology). This feature is available on select digital broadcasts and streaming video, and is not supported on standard cable or analog stations.
If the content does not contain a digital audio signal, then no sound can be heard through this connection. A secondary analog connection can be used to pass the audio signal in this situation. Additionally, sound sent to the TV through an HDMI[emoji768] connection or other input also may not output through the optical jack. In this case, the optical jack from the source device (Blu-ray Disc[emoji768] Player, DVD player, cable or satellite box) should be connected directly to the home theater or stereo system to get the sound.
Follow the steps below to troubleshoot if the optical jack does not appear to be working.
NOTE: Each of these steps represents a possible solution to no sound being heard from a TV when using an optical connection to a home audio system or sound bar.
Set the home theater or stereo system to the appropriate input and mode for the optical connection.Firmly connect the optical cable to both the TV and the home theater or stereo system.Try changing the channel on the TV to another digital broadcast.Go into the Sound or Speakers menu of the TV and select External Speakers or Audio System.
IMPORTANT: Some TVs require that the internal speakers be turned off before outputting the audio signal to another device. This step turns off the internal speakers.
Update the TV to its latest system firmware.
Replace the optical cable.If the issue is still not resolved, disconnect the optical cable and use an analog connection to output the sound from the TV to the audio system.
NOTE: If using a source device (such as a cable set-top box, satellite receiver or DVR) to get the signal to the TV, you may also be able to connect this device to the audio receiver using an optical connection. The following image provides an example of this type of connection:
Obs: no teu caso (ao contrário da figura, tens de conectar o cabo óptico na saída óptica da TV.
8. Perform a factory reset.
For the KDL-xxR550C series, set the following:
Press the HOME button.
Select Settings.
Select Preferences.
Select Setup.
Select AV Setup.
Select Digital Audio Out.
Set it to PCM.
https://us.en.kb.sony.com/app/answe...-through-the-digital-audio-(optical)-out-jack.
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