In previous iphone repair cases, we often encounter iPhone7 and iPhone 7 Plus leakage or won't boot problem. So, in this article, we are going to share solution for DIY fix it.
Disassemble the iPhone, remove the motherbaord and put it under the Trinocular Stereo Microscope to check, and then check iPhone schematic diagram on WUXINJI Dongle, we can know that the battery voltage VBATT is firstly sent to
the iPhone 7 charging IC, it outputs the main power PP_VCC_MAIN and then supply to
the power supply IC and other related circuits.
When the iPhone power button is pressed, the IC output voltage of the power supply is supplied to iPhone 7 CPU, NAND and other related circuits respectively. The battery voltage VBATT and the main power supply VCC_MAIN are sent to the relevant circuit before turning on the iPhone 7, in this case, if there is power leakage or large current when connecting with DC power supply, it means that either the battery voltage VBATT or main power fupply PP_VCC_MAIN has short power leakage component. There are plenty of components are connected with these 2 circuit, use rosin will help you to find the damaged one quickly.
Specific methods are as follows:
1. Measuring the of the grounding resistance of
the iPhone 7 battery voltage and the main power supply to find the
short-circuited part
3. Then add voltage in the short-circuited
part, the voltage will gradually increase from zero, after a while, the
short-circuited part will heat and rosin will melt, so you will see it
immediately.
After find the faulty part, use QUICK 861DW to weld the jimper wire on it, and then measure it again. You will find the problem was solved!
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