Ursprünglicher Beitrag von: Minho ,
It sounds like you are very comfortable doing micro-soldering repairs and BGA rework. The WLAN & BT are controlled by the same chip and you have already replaced it with a new one (or reball?). Did you check the voltage rails going to the chip? Perhaps the problem is coming from the PMIC? Did you remove the shields prior to cleaning the board? Perhaps there is some corrosion happening underneath them.