Here how to solution fix on Vivo Y81i (Vivo 1812) when connect usb charger show (unable to charge please contact our after sales service)
How to fix:
* Please check USB Charging Port, Chark Dock USB Connector, Charger Port Board and make cleaning ( if still not work ) continu to looking for check (Battery Connector ) with Mother Board also clean if still ( not working or unable to charge). Check and replace IC charger if still (unable to charge please contact our after sales service)
Please make Jumper by wire as image below.