IPhone 12 Pro max phone is not turned on for repair

According to the point bitmap, measure the battery connecting seat position and find that the battery seat position is short-circuited; It was found that a capacitor next to the CPU on the B side of the upper layer was short-circuited. After replacing the capacitor, the fault was repaired.

IPhone 12 Pro max phone is not turned on for repair.

Machine model: iPhone 12 Pro Max

Malfunction: the phone doesn’t turn on.

Maintenance process:

I received an iPhone 12 Pro Max failure machine, and the description of the failure is that the phone is not turned on.

After getting the mobile phone, the test shows that the fault is the same as that described by the customer. The mobile phone can’t be turned on, and the electricity leakage is short-circuited.

Power leakage short circuit is generally caused by the short circuit of the battery seat connected to the power supply. Check the primary power supply circuit.

IPhone 12 Pro max mobile phone is not turned on for maintenance figure 1

Open the annotation map of Xinzhi and find the battery connection seat.

IPhone 12 Pro max mobile phone is not turned on for maintenance figure 2

According to the dot map, measure the pin position of the battery connector, and find that the pin position of the battery connector is short-circuited.

IPhone 12 Pro max mobile phone is not turned on for maintenance figure 3

Smoke the yellow area with rosin, and then power up the main board. The melting part of rosin is the fault point. Operating on the A side of the motherboard, no faulty components were found. The main board is layered, and then the other levels of the main board are powered and burned.

IPhone 12 Pro max mobile phone is not turned on for maintenance figure 4

It was found that a capacitor next to the CPU on the B side of the upper layer was short-circuited. After replacing the capacitor, the fault was repaired.