I've discovered that the Turbo has a Red LED located on the motherboard, which is somehow tied to the motion sensor. It is barely visible in complete darkness, peeking out of the bottom left corner of the phone in the capacitive button area. It glows dim Red sometimes while the phone is motionless, but gets brighter when you move the phone slightly. If you move the phone to much, then Active Display comes on. It seems to be there as an indicator for troubleshooting or confirmation of the motion sensors being functional. I'll try to get some pics of it later. Had anyone else seen this?