Apologies for the delayed reply but I searched through lot of available information and I dont find any way by which we can turn off the backlight on these phones at the moment
So may be we can assume here is that at the moment its not possible. The reason to believe this is that generally for a IP telephones this is controlled in the firmare. I checked through the bin file for these phones and dont see available options
My suggestion would be write an query to the Avaya solution suppor team at [email protected] to confirm if this feature has indeed being incorporated in the design
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