4 steps to solved unknown error 9 on iPhone 6 Plus

Are you ready to fix your iPhone?  It can’t turn on , just infinitely reboot.  After we root it, it reports unknown error 9.  Is that enough?  Now, we can use 4 steps to solved this problem



  1. Disassemble the iPhone 6 Plus, remove the CPU. Because if dropped iPhones reports unknown error (9), mostly the CPU pins connected with logic board are missing. Measure U16X EEPROM IC , finding it is pseudo soldering. Solder CPU and jump wires, as shown in picture 7-36.


  1. Get into IOS and test it, the screen is blurred sometimes. Check display circuit and we find that display power supply PP5V7_LCM_AVDDH near display screen FPC socket is abnormal. PP5V7_LCM_AVDDH is output by chip U1501, as shown in picture 7-37. At U1501’s peripheral capacitor C1569, I measure its output voltage. The voltage is normal. The location of C1569 on motherboard is shown in picture 7-38.


  • We can’t find any voltage at C2071. U 1501 outputs PP5V7_LCM_AVDDH and transmits it to display socket passing by FL2037, as shown in picture 7-39.


  • Measure inductor FL2037 and it is workable. The location of FL2037 on motherboard is shown in picture 7-41.


  1. Thus we can be sure that motherboard is disconnected somewhere. Jump a wire to connect the disconnected place, as shown in picture 7-42 and 43.


  1. After jumping the wire, turn on the iPhone, it can enter the IOS normally, the problem has been solved. The iPhone 6 Plus back to health.



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