My LG G3 stylus (D690) won't turn on, what should I do?

[AC Question]

My LG G3 stylus (D690) won't turn on

I connect my phone with LG PC suit for the phone software update. After 99% it hang on, i try this for several time but same thing happened. i remove the battery and press the power button but phone can't turn on. I try hard reset (power+volm down key) but phone can't turn on. it can't find usb connection also. What should i do now