LG OLED no audio over ARC when using HDMI ARC connection.

[Wyatt21]

New LG OLED C7 with HDMI ArC connected to Marantz AVR about 5 years old. AVR can handle DD+/TrueHD but not Atmos. Marantz is hub. TV Sound set to HDMI ArC with Simplink on and digital sound to auto. On AVR HDMI control is on. AVR recognizes DD+ signal from TV l, and all I get is clicky staticy noise. No audio from content. If I am just viewing Netflix landing page with stereo I get audio. If I change TV audio to PCM output l, I get stereo audio but can’t get DD+/5.1 Audio when watching the Crown for example. Just replaced HDMI cables thinking that could be issue and no luck. Reset TV to factory settings and no luck.

 

[akagi1945]

LG responded :

"In response to your inquiry, according to the product support page of the OLED65B7P TV, a software version (Ver. 04.70.36) has been released to improve the Dolby no audio symptom exhibited by the unit when using HDMI ARC connection."

 

[Wyatt21]

Fixed!

I tried working around this problem with optical. It works but lost my HDMI CEC function as I had to unplug the HDMI cable to get the optical signal to work. Apparently the ARC is the problem.
That being said, I decided to try the Amazon Basics cable 10’ for $8. I have been using a high speed 4K Monoprice cable which worked fine until a few days ago. Anyhow, the new cable is working fine. Giving me back full ARC functionality. Amazing! Found this fix in another thread.