Hello Guys,
Don't get hyper and contact OPO's customer support. They are short on staff so it will take forever to get a solution.
The solution for the not charging problem is this :
"In My Case, I did the following steps...
After getting a full black screen (even no "low battery warning" screen after 1 day) and not even boot into recovery / fastboot...
===========================================
1) Kept the phone for 12 hours without touching and charging...
2) Plug official charger and usb for a moment... and tried booting... Nothing happend
3) Charged with official charger and usb for 6 hours and then
4) Pull off the usb and put back again ... and i got the LOW battery screen again,
WOW,
staying for 4 / 5 mins...
5) Now don't try to boot or anything.. keep it charging for 30 mins more and let it be charged
upto atleast 10% (you will see normal charging battery icon screen) even
it is black.
6) Now finally boot your device by pressing power button for few seconds
7) Phone should boot normally...
================================================"
Source & Much More Info here :
https://forums.oneplus.net/threads/...een-opo-not-booting-due-over-discharge.88107/
And I advice all OPO owners to follow the OPO forum regularly.