The iPhone 7 Plus rear camera is unavailable, but the front camera works good, what's going on? How to fix it?
Fristly, diasassmeble the iPhone 7 Plus, remove the iPhone rear camera, install the new one, and then test it, the iPhone rear camera still not working.
Disassemble the iPhone, take out the iPhone motherboard, we found the iPhone WIFI IC and iPhone audio IC was repaired before. As we know, the iPhone camera power supply transfer tube on the WIFI IC are easy
to virtual weld. So, we remove it, and then re-weld it, but the iPhone rear camera still not working.
Use digital multimeter to measure the grounding resistance value
for iPhone rear camera J3001 and J4501, the data is normal. And the power
supply for camera socket tested also is normal.
Measuring the I2C bus on J3001 and J450，when
measured the J3001 2 pin, finding that it only has 0.4V voltage, but in the
normal case, the normal voltage of I2C bus should be around 1.8V.
Open the WUXINJI Dongle to check iPhone schematic diagram, this
I2C bus via safety resistor R3301 to M2600, pull-up supplied by R4604 resistor.
Combine iPhone bitmap to find R4604
resistor, one side of the resistance value measured
of R4604 is normal, the other side is 0.4V, which is obviously wrong，we suspect
the pull up resistor is damaged.
With the help of the QUICK 861DW hot air rework station and tweezers, we
replace the pull up resistor, and the measure it again, now the both sides
voltage of resistor are back to normal.
Install the iPhone, get into IOS, tap iPhone camera icon, the iPhone rear camera is available now, switch it to front camera, aslo works properly.
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