I think that's incredibly unlikely. All that stuff is handled within the single chip "system on chip" (SoC) Broadcom special-purpose computer, and audio data is not routed separate from video data external to that chip (except to drive the analogue outputs).does that mean that the sound card or wherever it is has failed?
That's a separate question for a separate thread, and one I can't personally answer anyway.Is it possible to search recordings to locate a particular Title?
Thank you all for your advice. After much further fiddling, I have found a solution.
One of the TV audio settings is HDMI mode1/mode 2, the latter being the default. Changing to Mode 1 has now produced audio.