LG G3 LS990 wont power on

A

AC Question

What can I do when my lg g3 ls990 wont power on, dont know if its charging ( no led lights). Although, it did turn on for a split second when I connected it to a RAVPOWER ACE SERIES model: RP-PB052 capacity 22000mAh/83.6Wh
Output:iSmart DC 5V/5.8 total (each 2.4A Max). Long enough to show battery is at 41% then then it disappeared, hasnt turned on since. It also turned on once before when I try to turn it on, the lg logo came on, then the screen went blue and then black.
Anyone with a real solution?