I didnt charged my Galaxy Gear and it was dead from 1 month. Today when i tried to charge it, i was unable to charge as nothing was displayed on screen. So, this helped me and my gear booted.
Here is the solution guys, turn on your laptop or PC and plug it with USB cable. For some reasons gear need just a little a little power to turn on.
try until it wont start. try to press power button while charging it with your PC( i kw its hard just use some tool to press power button)
This is the only method it would boot up, and when its 5% charged you can charge it with regular power supply.
Thanks,
Nikhil Jassal