Hi, again.  I found the audio to be working this morning, after the computer had been off for the weekend!  I had rebooted as part of my investigation, but that appeared to have had no effect.  Anyway, all appears to be working now.
Hi, My Inspiron 5770 just installed Windows updates and (I think I saw) a firmware update.  Since then I have no audio on this computer.  I have run the diagnostics and the hardware is reported as working.  What should I do to restore audio? Thanks.
Inspiron 5770 Lost Audio