Apple xr cannot be activated after formatting.

Ordinary mobile phones cannot be activated: the system version is low; The baseband is not recognized; The CPU does not recognize the NFC chip; Hard disk serial number and Bluetooth WIFI address do not match. The mobile phone hasn't been repaired yet. First, rule out the case that the serial number of the hard disk does not match the Bluetooth WIFI address. The serial number can be seen in the activation interface of the boot test mobile phone, which does not rule out the situation that there is no baseband.

The reactivation fault of the brush machine is still the same, and it is judged that the problem lies in the NFC circuit. Disassemble and take out the motherboard, and observe that the NFC circuit is actually repaired under the microscope. When the chip is directly removed, it is found that the REF resistance of NFC chip is abnormal and infinite.

Open the bitmap of Xinzhi contrast point, and a capacitor C7534 is connected to this line. After removal, the resistance value is normal. Replace this capacitor and put it back on the NFC chip. The startup test was activated successfully, and all functions were normal. Maintenance is over.