Water Damaged logic board advanced question

so a customer brought in a 6 plus for water damage repair.most, if not all of the corrosion was on the top of the board near the screen fpc connector and home button fpc and a small amount on the 1.8v line next to the nand memory. removed shields, ultrasonic cleaned, and found the shorted cap on vcc main that was stopping the phone from powering on. then after that i connected it to dc power supply and it drew .03a with no button press. however if i try to power it on it boots and makes it to the lock screen, i can even get in the phone, but then after a minute or 2 it reboots. any ideas?