The XdA has some built in features to minimize the amount of light that it gives off in
use and keep prying fingers from misadjusting it.
When first powered up, the text on the front panel is illuminated. If neither Mode
button is pressed for several minutes, the XdA goes into a lockout mode (no lights on
except for the power light) where pressing either of the Mode buttons has no effect.
To get the XdA out of lockout mode, press and hold down both Mode buttons for at
least 2 seconds. The text on the front panel will become illuminated and the Mode
buttons active.