Chosen Solution
My iphone is stuck on black screen (DFU Mode) and Pressing Home and Lock button does not work,and it come backs to the DFU Mode It’s really DFU mode detected by 3UTools,also tried other softwares and it’s not recovery mode! and restoring it says Error restore 4014 then 3utools says it’s invalid serial number. After 2 days it ran out battery and then i tried to restore it and it works again, And after 1 Weeks or sometimes it lasts months it goes to black screen/dfu mode again, In short,I HAVE ALWAYS TO RESTORE EVERY LONG PERIOD OF TIME, It’s absolutely UNUSABLE because i always have to start all over again the progress on my iPhone! I Also replaced the battery 2 TIMES,Replaced the screen too! and still getting this problem!!! I also tried changing usb cable,tried another PC also tried MAC,AND EVERYTHING SOFTWARE SOLUTIONS THAT I SEE AND ALL OF THEM DIDN’T HELPED AND STILL GETTING THE PROBLEM!! PLEASE HELP!!! i’m buying new iPhone in september but this iPhone is very special to me! Please tell me what hardware error is this!!,it auto boots to DFU Mode and it’s very grueling because it prevents the iPhone to enter Any modes and it needs to be drained to make it able to enter recovery mode! For now the iPhone is broken again,PLEASE HELP ANYONE! I WOULD THANK YOU A MILLION FOR THE SOLUTION!!
No idea why some 5s does this probably liquid damage under baseband chip.
99% it is the nand on the motherboard. 4014 leads to nand and if you remove the nand from a board and try to restore in 3u it will say invalid serial number as it cannot read it.
