M401/M402/M403 control panel is composed with LCD, 27 buttons and 1 status notification LED and
lamps on 8 buttons (copy, scan, fax, dial, redial, A3/11x17, start, power key) get turned on.
M400 control panel is composed with LCD, 11 buttons and 1 status notification LED and lamps on 4
buttons (copy, scan, start, power key) get turned on.