Chosen Solution

Hi All, I just bought a second hand iphone 5s and update the ios to 10.2. It works fine for almost a day and at the end of the day suddenly the device blank screen and what i did was reboot it as the screen are not coming back after i press power button to awake it. The device will never reboot and stuck at boot logo. Throw me a panic cpu 0 caller kernel panic once before stuck at itunes logo. Tried to perform itunes restore but keep getting error 4013 on normal recovery mode and error 9 on DFU mode. Tried to remove front screen assembly and back camera that someone from the answer here suggested but still unable to solve my issue. Any other parts might have cause this? Your suggestion of potential fix are appreciated. Local device repairer told me might be the u2 flash issue and not worth for a fix as to replace the ic is expensive, is that true? Thanks

error 9 while in DFU mode means lost connection between PC and device…. I would try replacing the USB cable first… if the issue persists then it should be an issue related to U2, Q2 or Power Manager, depending on measures taken with multimeter along the related voltage lines… I don’t know what your local repairer means for “not worth” to repair… Here in Malta where I operate we manage to fix these issues for a maximum 200eur expense… maybe it could be worth for you or not…. in my opinion when a repairer tells you “not worth” without quoting it’s because he’s not able to fix it… this to encourage you not to give up and search for alternative repairers…. good luck!