First of all, use screen opening tools to disassemble the iPad Air 2, remove the iPad display screen, disconnect the iPad battery and then remove the iPad motherboard.
Put iPad motherboard under a Trinocular Integrated Microscope to observe, we found the iPad screen connector on the iPad motherboard is burned out, and there are signs of water corrosion.
The iPad Air 2 accidentally fell into the water, and after being removed for some dry water treatment, it could not be opened.
Replace the new iPad screen flex cable, and then connect it to the normal iPad to test. After testing, we found the iPad screen is fine.
Now we are going to repair the iPad motherboard. Put iPad motherboard to DA-968 Mini Ultrasonic Cleaner for cleaning, after cleaning, we found there are many components are dropped, and there are few solder pads were burned.
Fill up the missing components, and then use SUNSHINE DT-17N Digital multimeter to measure the diode data for the iPad screen connector, we found then backlight power supply voltage PPLED_BACK_REG_A has no value, which is abnormal.
Log in to the ZXW online account to check iPad schematic diagram, we saw that PPLED_BACK_REG_A passes capacitor and then connected to the diode D8428.
Find out D8428 on the bitmap, directly solder a jump wire from diode negative to screen connector.
Because the circuit that connected to 15 Pin is corroded, check iPad schematic diagram, we know that this Pin voltage is the iPad screen fingerprint 1.825V power supply PP1V825_S2R_MESA_FILT, the chip position that produced this voltage is U4750, which is also corroded seriously, and its solder pad is dropped and cannot be soldered again.
Therefore, we need to borrow a 1.8V power supply from other place. According to the iPad schematic diagram, we found the nearest 1.8V power supply is PP1V8_AUDIO of U3250 audio amplifier chip, so we solder a jump wire from C3252.
Now assemble the iPad Air 2, press the power button, the iPad Air 2 can be turned on successfully. Test the function on the iPad Air 2, all works well; the iPad Air 2 has been fixed.
The method we shared with you can help you fix a water damaged iPad Air 2. If you have other method to fix water damaged iPad, please leave a message in the comment.