Try using the original adapter to charge or another that supports the same voltage and ampere. Another solution is to disassemble the phone, disconnect everything from the main board and then reconnect.
Hi That's not a smart idea, but if the external battery doesn't go under 30% and is the same ampere and volts it should be fine but I still advise you to connect the internal battery for the safety of the headset.
Hi Your Phone is boot looping and the fixes for it are the following: (1) Tare it down and disconnect the main board then reconnect it. (2) Try entering recovery mod (Make sure its powered off and has battery, then hold power and volume down at the same time until you see the logo, then navigate to factory reset via volume buttons and to select use power button.)
Hi You should check the cable inside. it may be broken or something. Find replacement or check the ports of it and move it a bit till something happens.
