iPhone 6 Plus Error 4014 Repair after Nand Replacement
According to customer's description, there were no any problems on his iPhone 6 Plus before, it can be normally used before, t. But after changing the iPhone Nand for memory capacity expansion by himself, it reports error 4014 when flashing it. As shown in picture 10-3-1.
When we flash the iPhone device, it displays error 4014 before progress bar showing up. It is restored and the serial number could be recognized, which appeares after Nand expansion. This is usually caused by the iPhone USB chips leading to CPU problem. We get to know it UMT motherboard after disassembly, then remove USB chip U1700 to measure resistance from solder pad to CPU, we find that AP_TO_TRISTAR_ACC_UART6_TXD shows the infinite value, as shown in picture 10-3-2 and 10-3-3. And AP_BI_12C0_SDA is also broken, as shown in picture 10-3-4 and 10-3-5.
The layer wire is disconnected, so we need to find out other connection point or digging for other holes, AP_TO_TRISTAR_ACC_UART6_TXD is direct connected without other external components, when digging the circuit AP_TO_TRISTAR_ACC_UART6_TXD we find that there is a hole next to socket, dig it to solder jumper wire. As shown in picture 10-3-6, 10-3-7 and 10-3-8.
AP_BI_12C0_SDA has a test point outside of the iPhone circuit board, welding directly from the test point. As shown in picture 10-3-9 and 10-3-10.
Intall the iPhone USB chip back, we can flash the iPhone device normally now, repair ends here!
More phone fix information, please check on www.vipfixphone.com
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