Detailed Solution for iPhone 6 won't boot after dropped into water (short-circuit)

If the iPhone dropped into water, then you must have the idea that the iPhone motherboard is damaged.  Moreover, the iPhone won't boot. After water damaged, the most common phenomenon is the short circuit on the motherboard, and there has two cases. Let's take iPhone 6 won't boot after dropped into water as the  an example.

 

The water damaged the iPhone 6, now the problem is that the iPhone 6 won't boot.

First of all, we need to disassemble the iPhone, take off the iPhone motherboard, and then measure it with DC power supply.

Case 1

When supply power to measure the iPhone motherboard, there is large current alerts on DC power supply display screen, which means that there is a leakage phenomenon. Generally, when powering the motherboard and then it shows power leakage issue, the Rosin method is the best choice.

Use Fluke 15B+Digital Multimeter to measure the diode data for iPhone battery interface positive, the data is normal. Continue to measure the diode data for main power supply VCC_MAIN circuit, finding that the diode data for this circuit line is too small, which means that there is a short circuit here.

Smoke the iPhone motherboard to white with rosin, add voltage on VCC_MAIN, after for a while, we found a capacitor is shorted.

With the help of QUICK 861DW rework station and tweezers, we remove it smoothly and quickly. After remove that capacitor, measure it again, the data is normal now.

Install the iPhone to test, the iPhone 6 can be turned on smoothly.

Case 2

When the iPhone motherboard is being measured by powering, it won't leak, but when we press the iPhone power button, the current stuck on 200mA. Obviously, a load on the iPhone power IC is short-circuited.

Use multimeter to measure the resistance of each output grounded on the iPhone power IC, when the PP1V8_SDRAM circuit is measured, we found the problem, the PP1V8_SDRAM circuit is shorted, because the data for C1243 is too small.

Put iPhone motherboard under the Phone Repair 7-45X Trinocular Stereo Microscope, and then apply some rosin on motherboard, and then use Quick 861DW hot air rework station to smoke it, till the motherboard turns white.  Increase the voltage in the C1243, after a while, we found a capacitor is shorted.

Remove this capacitor as usual, and then measure it again, now the data is normal.

Assemble the iPhone to test; now the iPhone 6 can be turned on smoothly. After get into IOS, test all function on iPhone, everything works well.