It's now suspect and needs to be out of the system.
Just finished an addition to my home and in the process got a new dedicated room for a home theater. I've been hooking up all the equipment and wiring myself, as I'm the aspiring DIYer and low voltage stuff is pretty easy.
I'm having an issue where audio (and sometimes video) cut out with my new equipment. Please see details below.
First, a little about my equipment.
TV: LG OLED77C9PUB
Receiver: Yamaha RX-A780 AVENTAGE 7.2
Primary Source: Fire TV Cube (new Fall 2019 version)
Cable from Receiver to TV (Connected in ARC 1 at rcvr and Input 1 on TV): BlueRigger 4K 10 ft HDMI
Cable from FireTV to Receiver (HDMI Input 1): Twisted Veins 3ft HDMI
Speakers aren't probably relevant but it's a 7.1 Klipsch system. Everything is 14-gauge speaker wire shielded pairs with transparent jacket. Made the connections to the wall from the receiver with Amazon Basics banana deadbolt plugs.
All equipment is brand new.
First Problem (Solved? Related?)
I was running the FireTV directly to input 1 on the TV using the BlueRigger cable for a couple of days. At first I had an issue when I set the FireTV to 4K. There were lines that looked like frame tearing appearing all over the screen and flickering everywhere. Turns out one of the construction guys tied that cable up really tight and ziptied it without telling me. When I cut the ziptie and loosened the cable everything seemed to work fine in 4K mode. But this problem may be related to the one I'm having now...
After introducing the receiver and speakers to the ecosystem audio (and sometimes video) cut out periodically. Every couple of minutes or so, and for 1-2 seconds at a time. Audio much more frequently than video, but if video goes out the audio always goes out with it. This is across multiple apps, though I've only tested the FireTV. The Twisted Veins HDMI was also introduced at this same point to create the connection between the FireTV and Yamaha.
I am fairly confident there are no speaker connection issues. Here are pictures of my receiver when everything is working as well as when the audio cuts out. Ignore that you don't see all speakers shown on the panel, I was testing with a smaller set of speakers to easily diagnose.
Issue is also unlikely to be ARC. While I've read numerous stories of how ARC is not working right on some LG TVs, the issue seems to clearly exist at a point in the system before my TV is involved.
TL;DR Everything seems to point to an issue with the source, an HDMI cable (HDCP compliance handshake?), a setting, or the receiver. I certainly hope it's one of the first three.