iPhone 7 water ingress damage not turn on for repair

Machine model: iPhone 7
Fault phenomenon: mobile phone water damage no booting

Maintenance process: power on short-circuit current 900mA no power on, remove the main board, observe that Capacitor c2307 is broken, two coder amplifiers have corrode.

iPhone 7 water ingress damage not turn on for repair Figure 1.

iPhone 7 water ingress damage not turn on for repair Figure 2.

When Capacitor c2307 is removed, part of water damage is cleaned. When short-circuit current 100mA is powered on, the switch can be started normally. After testing, the machine is free of vibration and sound. The two coder amplifiers are removed and the secondary volume value is checked. It is found that u3402 A2 pin 30 is more than 300 normally, and only m2800 is connected to A2 pin.

iPhone 7 water ingress damage not turn on for repair Figure 3.
It seems that the m2800 is damaged. Remove the m2800 and replace it.

iPhone 7 water ingress damage not turn on for repair Figure 4.

After replacement, measure u3402 A2 pin Diode value is normal, replace two coder amplifier chips, power on the machine is no longer short-circuit current,switch is normally started, sound and vibration are normal, this is the end of maintenance.