IPhone 7Plus does not turn on (short circuit of power supply of power amplifier)

IPhone 7Plus does not turn on (short circuit of power supply of power amplifier)

[Fault model] iPhone 7Plus

[Fault phenomenon] No boot.

[Maintenance process] I received a machine sent by a customer for repair, the model is iPhone 7Plus, and the fault is that it does not turn on.

IPhone 7Plus does not boot Figure 1

When the motherboard is removed and powered on, it means that there is a short circuit at terminals 1 and 2. Measure the resistance of the main power supply, which is 0001. The main power supply is short-circuited. Let’s burn the machine directly or see if we can touch it out by hand. When touching it, we find that the heat in the shielding cover next to the socket at the end of the motherboard is serious. Remove the shielding cover directly. When it is powered on, we can feel that it is a power amplifier power supply chip that is hot and remove it directly.

IPhone 7Plus does not boot Figure 2

IPhone 7Plus does not boot Figure 3

After measuring the resistance of the main power supply, it recovered more than 340, indicating that the short circuit was caused by the damage of the power amplifier chip. Replace the power supply with a new power amplifier and put it back on the motherboard, and the card signal is normal after starting the test.

IPhone 7Plus does not boot Figure 4

[Maintenance Result] Install the motherboard into the shell.mobile phoneIt can be turned on normally, and the functions of WiFi, Bluetooth, voice, charging, fingerprint, taking photos and making phone calls are all normal, so the maintenance is over.