Yesterday, we received an iPhone 6, which has screen failure, the iPhone screen is blurred, we try some softwware solutions, but not working, we also try to fix it by replacing iPhone scree, but still failed. So, we suspected that it's the iPhone motherboard problem.
Use screwdriver to remove the srews next to the iPhone lightning port, put iPhone 6 on the CPB screen separator for a while, and then open the iPhone 6. Remove the iPhone display assembly and iPhone battery, and then take out the iPhone motherboard.
Observe the iPhone motherboard, we found the
upper part is seriously deformed. Use digital multimeter to measure the grounding resistance value of the iPhone display socket
J2019, the resistance value all is normal.
Put iPhone motherboard under the Trinocular Integrated Microscope, remove the iPhone display IC U1501.Measuring the grounding resistance value of
the iPhone display IC J219, we found the A4 pin is shorted, A4 pin touch 5.7V
power supply, it is connected to iPhone black touch IC and some filter capacitors.
Because the
upper part of iPhone motherboard is deformed seriously, and the iPhone black
touch IC is easy to damage, so remove the iPhone black touch IC. However, it is still short-circuited after
remove the iPhone black touch IC, seems it's not the problem of the iPhone
black touch IC.
Next we need to use QUICK 861DW hot air rework station to remove the
filter capacitors that connect to it, after remove the filter capacitor C1577,
the resistance value is back to normal. Re-install the iPhone black touch IC
and iPhone display IC.
Now, install the iPhone, charge the iPhone 6 with iPhone lightning cable, after a while, power on the iPhone, now we can see Apple logo appears on iPhone screen, the iPhone screen displays normally. Test other functions on iPhone, all works perfectly.
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