I have a reproducable problem, if I use the netflix app and watch it for a while and then use goback to get to netflix main menu and then use the exit menu option within the netflix app to exit it, then the TVs audio is not working anymore. Mute/Unmute does not help, switching channels does not help. I have to turn the TV off and on again and after that the audio works. I am using the builtin speakers, nothing connected to the TV.
Software version: T-KTSUDEUC-1300.4
And by the way, the update from 1295 to 1300 only worked from USB Stick.
Update: Might be the same issue as reported in posts:
Sound issues with my Samsung NU6900 series tv UN75NU6900
Thank you for reaching out! This forum is for the support of US products and customers. As your product is a non-US model and support for these models is very limited, please seek a support team for your area. You can do so by using this link: http://www.samsung.com/visitcountry Thanks!