I had old kpl, and when the lights were on, there used to be dim backlight to show the names/buttons of the pad, and when turned on, button used to get brighter to indicate its on. I changed to 2334 and its totally dark / off if the lights are off. hard to tell in dark if there is a KPL and the switches. was this on purpose? anyway to turn on dim backlight ? is my KPL defective?