Solved: iPhone 7 Plus got unknown error 56

This iPhone 7 plus got unknown error 56 during the restore, after tried some software solution, the error 56 still there. Now,we need to check iPhone 7P motherboard.

After measure the iPhone camera circuit by digital multimeter, there is no abnormality in the resistance value of the power supply of each circuit of the camera. Check the NFC section, there is a common fault in the iPhone 7P. The NFC power supply tube in the upper left corner of the CPU can be connected short first

Short connect the A1 and A2 pin on the NFC power supply pipe, then restore to test after short connection. This iPhone 7P is still not able to pass after that, so we can only take NFC to test.

It is no problem to test the resistance of the socket by Fluke digital multimeter(VC712), reball the NFC module with iPhone BGA reballing stencil, install the NFC module and restore the phone after installation, but the mobile phone does not carry out the second self-examination and jump to iTunes, computer display recovery mode. There was no such situation before, so the first thing was to go out and exclude it. In order to prevent the external device from entering iTunes directly in the case of short circuit, when the computer exits the recovery mode, the iPhone volume flex cable and the tail plug flex cable interface are still not touched.

We did not expect this will happen on other places, the system is the latest, just choose to retain data to restore the machine, then discuss with the customer to decide a new reflash without retaining data, it gets normal access to the activation interface.

Finally, install the iPhone, get into IOS to test other functions, everything goes well.