Thanks to this forum, I learned that the keyboard backlight doesn't light up in daylight. But if you move it somewhere dark or at night, it does lit up. Very nifty. Nonetheless, I think that my KB backlight doesn't always work when it's supposed to. I'm not sure if this is an actual error in my phone or that it has something to do with certain applications, since I've noticed that it doesn't always light up (even at night) when I'm chatting via WhatsApp. Anyone else have experience with this? ETA: My phone's not rooted and the brightness of the screen is set on automatic, in case that's relevant.