When I'm clicking the next button fast(through commercials) sometimes it 'Mutes' the sound. This is a 'cable' mute not a set top mute. An indicator comes up in the upper right hand corner.
However there's no way to Unmute it. Clicking the MUTE button doesn't work. Nor does hitting the volume buttons.
I've had to reboot FIOS whenever this happens(unplug the box).
menu> settings> audio video> audio, make sure audio volume is all the way up and volume control is set to fixed.
Also check what audio options are set. E.g. if Dolby Digital is set and your TV doesn't support it, you will get no sound from some channels.
Just had the same thing happen to me... The mute notification came on my screen via the FiOS box, not the TV, while skipping ahead 30 seconds. I managed to fix it by connecting to my box via the Fios app.
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