Troubleshooting: HDMI & video

HD works and 4K HDR does not: that is a bandwidth problem, and the usual suspect is the cable or a port. One of the few AV problems where the cheap fix is also the correct one.

That is HDMI-CEC doing its job, just not the job you wanted. CEC is the control channel that lets devices switch each other on, change inputs and share a remote. Useful when it behaves, maddening when devices from different brands interpret it differently.

Normal, not a fault. When audio routes through the TV, each app is on its own, and three things must cooperate per app before surround reaches your AVR.

Lip-sync error is a processing mismatch, not a fault. TVs take longer to process video (scaling, motion smoothing, HDR mapping) than AVRs take to decode audio, so the voice arrives a few tens of milliseconds before the lips move. Once set, it rarely needs touching again.

Nearly always the connections, not the electronics. A momentary dropout every few minutes is a link renegotiating, not an amplifier failing.

Isolate by swapping. No tools, no multimeter, and in three steps you will know whether it is the speaker, the wire or the AVR channel.

That is an HDMI handshake failure: the copy-protection (HDCP) and format negotiation between source, AVR and TV is not completing, so the picture blinks, drops or never arrives. Common, fixable, and almost never a sign that anything is broken.

Work the chain from the AVR outwards. In our experience this finds the fault in ten minutes, and it is almost never a dead amplifier.