Curious. I don't happen to have my SX-2000 THB handy, but in the SX-200, from LW 16 all the way up to ICP, the Superkey is where you would find the Mute key. Or in Form 9*.
You are correct that "Microphone" is NOT the correct key, as that is for silencing a speakerphone only. My advice would be to review the Technician Handbook.
I found a reference to LW in the SX-200 Handbook, but that seems to be a trailing Letter from a specific model controller. Is lightwire something? That is printed on the cover of the SX-2000 handbook.
I don't see anything in reference to a form 9 or form 09 in the integrated HELP or the SX-2000 handbook. I did find it in sx-200 handbook. But I think that they scattered the form amongst different forms for the SX-2000 and 3300.
I searched both the SX-2000 and 3300 ICP handbooks, and the word MUTE isn't returned. I confirmed that it was searchable. It found the word handset a hand-ful of times. I will bring them home to see if manually searching, finds anything.
Thanks for some keywords.
