Answer to: Any tips for replacing the charging port?Please check out the touch screen replacement manual as far as the usb ribbon is changed. You may change it without the motherboard remove Step. So from Step 5 go directly to Step 9... It is easy. You will find replacement part on aliexpress site.
Answer to: cant hear music when earpiece is plug inI would replace the Jack that must be dirty or water damaged. http://www.aliexpress.com/item/Original-Headphone-Earphone-Jack-Audio-Flex-Cable-For-Xiaomi-3-M3-Mi3-Repair-Replacement-Parts/32248408846.html But it migth be Clever to buy underneath flex, just incase. http://www.aliexpress.com/item/Brand-New-100-Original-XiaoMi-3-MI3-M3-Proximity-Light-Sensor-Flex-Cable-Replacement-Part/32284179689.html Good luck Update: Replacing Jack is up to Step 4 no need to go after if it is working directly. Otherwise you need to all the way to ribbon with proximity sensor.
Answer to: Where to buy lcd screenThis is a place to start with. Double check the double sided tape to stick back all ribons. if not make sure either to find one from another seller, either to buy electronic double sided tape (quality 3m) and set it your self.
Answer to: How do I fix a broken display screen on my Xiaomi Mi 3?Follow new guide posted today