I went to put my watch on this morning and noticed the screen didn't wake from PS mode. Pressed all of the buttons and still nothing. Brought the watch to work and left it in the sun for a while and still nothing. Just the other day the watch was at the MID battery mark and nothing seemed out of the ordinary. Is the watch completely drained? Should I leave it in the sun all day? Replace the battery? Any help would be great. Thanks!