you can press the button 6 times, 5 of them being brightness settings, the 6th turns off the backlight but not the LCD. i find that 5 (the brightest) and 4 have about the same level of brightness, but 3, 2, and 1 definitely have different levels. i also hear the high pitched sound when the volume is very low, this was not something i heard during the review. i only hear it on levels 4-1. on 5 and 0 i do not hear it at all. i mostly play with the volume turned up or with ear buds, so i don't notice the high pitch sound while gaming. i wonder if anyone around me does?
are you able to game and use the firmware menu while its plugged in and charging? i can not, as i pointed out in the review.
-another world
Oups, my bad, I corrected my post.
Yes, I can use the revo without issue when plugged on the wall: game, menu, mp3.