Hi guys.. i want to share my story with my mi3 please listen i need some help. I had my mi3 for more than 5 months, until suddenly closed and never opened again(i tried EVERYTHING) i send it back to service they fix it by changing the mainboard, BUT when i received my mi3 back it has extremely fast battery drain, my mi3 cant handle more than 2hour screen on time(with cleared installed rom without any program/ also i tried many roms clearly installed) i have tried many times calibration apks i have tried full discharge/charge battery cycle, every time the battery life was the same...some times the battery falls from 14% to 10% immediately..so anyway i said is the battery and I CHANGED the battery with a new one.. GUESS WHAT..again screen on time maximum 2-3hours WITHOUT using it a lot only some sms/phone calls.. WTF i have to do now? what can cause the problem whaaaaat? when i bought my mi3 the battery life with heavy using it was 5-6hours screen on time, and now faiiiill.. what can i do? please tell me what i have to CHANGE again.. Maybe it is the antena that draining battery? because some times i have bad signal so is trying to find signal..(before many months when the phone was brand new i didnt have never problems with my signal) what can i do?