I've tried that and it didn't work.
A year and a half ago?? Oh man. Sorry to hear that. You could also use a One-For-All basic Universal remote to control the muting function. Try this, instead of simply unplugging the unit for 30 seconds, some units take longer to factory reset and power may need to be unplugged for up to 60 minutes. The other Expert definitely knows his stuff, but it would'nt hurt to try unplugging the unit for a bit longer to see if this clears the issue up. Let me know how it turns out.
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