IPhone 12 Pro Max cannot be started for repair Machine model: iPhone12 Pro Max Symptom: The phone cannot be switched on Maintenance process: A faulty iPhone 12 Pro Max machine was received. The fault description is that the phone can’t…
First, replace the screen. After replacement, the fault remains the same. Check the PCB wiring position through the wiring diagram of Xinzhi Manufacturing Board Layer. Scrape the PCB board, reconnect the lead of PMU_TO_DISPLAY_RESET_CONN_L, and repair the fault.
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.
When the mobile phone is turned on, the flower screen is found. Due to the universal tin-planting steel mesh, the CPU is removed again, and several spots are found to be soldered. After reinstalling the CPU, the mobile phone is turned on normally, and all functions are tested normally. The maintenance is over here!