Machine model: iPhone 6P
Fault phenomenon: weak WiFi signal, sometimes no WiFi
Failure analysis: rule out antenna problems, remove the chip to see if it is a virtual solder.
The signal is weak, remove the chip to find the 45 pin drop point, this point is just the 2G signal input of WIFI.
Repair point fly line.
Solder on the chip, installed test function all normal, fault repair!