My LG TV only have picure but not sound

[Ronen y]

It's a new LG 617 TV. 4K. I connected my PS4 Pro (4K) to it via HDMI cable and hear the sound of the operating system but not picture.
I connected the same PS4 to samsung TV (not 4K) and see picture. I connent my regular PS4 (not 4K) to my new LG TV and I see picture. What do you think is the problem?

Thanks.

 

[americanaudiophile]

Not every HDMI input on your TV may be HDMI 2.0 which would be required for 4K sources. Check the manual.
When you connect the PS4 to a FHD TV it doesn't need the HDMI 2.0 input since it detects the TV and changes to FHD instead of UHD.

 

[Natsukage]

Try it out in Safe Mode:
https://www.playstation.com/en-ie/get-help/help-library/system---hardware/power---system-stability/safe-mode-on-playstation-4/

Probabilities are you are having HDCP errors.