Repair Guide: iPhone 7 Plus won't boot after dropped into water

The iPhone 7 Plus won't turn on, the reason is that the iPhone 7 Plus accidentally dropped into the water while taking photos, after a day, the customers send it to use for repair.

Use phone opening tools disassemble iPhone to check iPhone motherboard; there are no obvious traces of water. And then remove all sockets, no traces of corrosion were found on the socket and the socket interface.

Connect iPhone logic board to DC power supply, supply power to it, it shows large current and won't boot.

Remove iPhone logic board and check it under the 7-45X Trinocular Stereo Microscope, we found that both the capacitor and the main supply capacitor on the bottom of the iPhone motherboard to backlight are corroded. According to our experience, for iPhone 7 or iPhone 7 Plus, we can first check the first row of capacitors on this circuit line, because we've repaired the several won't boot iPhone because of the large current caused by the capacitance.

Use PPD 861D Plus hot air rework station to remove C3530, the main power supply not short circuit now, and when we supply power to it, the iPhone can be turned on normally. However, there is no display after iPhone touch screen installation. After check it, we found that D3701 and D3702 have been corroded and blackened, directly replace it.

Install the iPhone and test it again, after insert the SIM card, the iPhone is always in the search signal, dialing *#06#, the IMEI can display normally, so we can eliminate the baseband problem.

Disassemble iPhone again to check, we found a chip next to the amplifier was missing. After check iPhone schematic diagram on WUXINJI Dongle, it is FL7001_RF. Directly weld a jump wire on it, and then install iPhone to test, now the signal is normal.