As we all know, keep your iPhone far away from the water, however, there's always an accident. Yesterday, my iPhone 6 fell into water, and then there is leakage when connecting it to DC power supply, which triggers large current. We need to fix it.
The
iPhone 6 motherboard waterproof stickers changes into red, indicating that the motherboard got into
the water, the power supply shows leakage
31mA when electricity is connected. As shown in picture 4-4-1 .
Short
start signal boot, current jumps into 223mA as shown in picture 4-4-2 .
This
kind of fault is usually caused by chip damage after water inlet, measuring
each power supply is normal value, measuring the datacable of the 12C0 bus to the ground value is only 002, indicating
that the 12C0 is short-circuit to the ground, the normal value should be about
400. As shown in picture 4-4-3.
Combining
the above phenomenon, the fault target is locked in the U1602 flash power
supply IC, U1503 fingerprint power supply IC, U1501 displaytouch IC, U1502 backlight power supply IC. We can see there is a
little oxidation around U1501, so remove it immediately then measure 12C0 to
the ground value is 352 (after board gets cool only about 400) ,as show in picture 4-4-4.
Connecting
multimeter, leakage current is only 001,
indicating that after the demolition of U1501, there is no longer leakage of
electricity, change a U1501 chip and then boot, the current normal jump, the
screen shows white apple, so here we succeed in iPhone 6 motherboard
maintenance. As shown in picture 4-4-5
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