Hi,
Just got my 840, firmware now on 24.54. Used a 830 for years.
When I power the unit up, the backlight appears to be not on, or at least very very low. If I go to Menu>Battery Saver then toggle this on (I have it off), the backlight comes on. I have the "Reduce Backlight" toggled off. I then disable the battery saver, and the backlight is working as expected.
I assume this is a setting somewhere that is new to me, as everyone cant have this problem every time they switch the unit on, surely?
Any help appreciated whilst I dig into the menus.