I have an S90C (model QN65S90C) and a Sonos Amp connected to stereo speakers. This setup worked perfectly with my previous TV (a 2012 Panasonic plasma) using ARC, but the S90C does not recognize the Sonos Amp as a valid ARC device. In fact, the automatic device recognition thinks the Sonos Amp is a Spectrum cable box. Both devices are running the current firmware, and I have tried using three different 8K-rated HDMI cables from different brands, and I have also tried to connect the Amp to two different Samsung S90Cs (this 65" QN65S90C, as well as a 55" QN55S90C in a different room) with the same results. I have to use the optical audio instead, which has a frustrating audio delay even when the delay is set to 0ms in the TV's expert settings. I'm not trying to use eARC so I find it hard to believe that the older ARC standard is causing such a problem. Any advice?
Following up on this, I received a warranty replacement Amp from Sonos and it worked immediately with ARC. I have no idea why the first Amp would work with the Optical-to-HDMI adapter, but didn’t with with HDMI-CEC, but I’m glad it’s working properly now!
