I had the same problem with the inclusion of the backlight on Altitrack altimeter. Reading the manual and notes from the forum nothing I was not clear. I could not turn on the light.
,,, How I did it. Short click on the right button immediately after that again click on the right button and hold it, but when there is a green LED light release the right button. Only then will turn on the backlight. Of course if you want to turn the same procedure.,,,
1. Press the Right Front Button and release quickly
2. When the green ACCESS indicator light on the front of the ALTITRACK dial
illuminates, immediately press the Right Front Button again and keep it pressed
(ACCESS indicator light goes OFF)
3. When the ACCESS indicator illuminates again, release the button immediately