We received a damaged iPhone 6 Plus, the problem is that after the iPhone 6 Plus has replaced the iPhone touch IC, it is now not able to boot. We need to re-repair it.
According our experience, we need to check where we've been repaired before. Testing it with DC power supply, it doesn't leak, and the boot current stops at 400mA.
Considering the touch IC has been replaced, the
last repairman directly took the black touch off without welding jumper wire on
touch M1 pin(6P can still boot normally without installing black and white
touch), but the current is same as before, measuring the starting voltage we
find the iPhone 6 Plus NAND flash 1.8V and I2C bus 0.6 V, so we doubt it is the iPhone power IC
problem. With the power on, it is indeed hot, with 400 degrees we quickly take
the power IC off, according to the symptom, it's necessary to confirm whether
the power supply IC is damaged, a good method is to measure the pin resistance.
The results of this 6P is measured as the power
of IC to 1.8V white touch power supply is short-circuit, now it can be judged
that 1.8V power supply short circuit pulled down the power of NAND and bus,
removing the white touch chip, short circuit fault is solved now, welding jumper wire on
black touch M1 and replace new chip.
Finally, assemble the iPhone, press the iPhone power button to test, now the iPhone can be boot smoothly and successfully.
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