Repair Guide: iPhone 6S Plus unknown error 4014

We received an iPhone 6S Plus need to be repaired on last week, the problem is that the iPhone 6SP reports unknown error 4014 when recovering it by iTunes. Here is the repair guide.

According to our repair experience, we know that most iTunes 4014 error is caused by iPhone Nand flash. In order to fix this failure, we need to disassemble the iPhone first.

Disassemble the iPhone 6S Plus by phone opening tools, and remove the iPhone logic board.

Use digital multimeter to measure the measure the power supply 1.8V and 3V of NAND, both are normal.

Use tweezers to remove the iPhone Nand flash, and then measure the grounding resistance value of the solder pad by digital multimeter.

After measurement, we found the M6 pin abnormal, the normal resistance should be about 1000, but the pin value is infinite.

Check the iPhone 6SP PCB pin and connect it to the external R1501 resistor. After checking, we found that the resistor R1501 is missing, replace R1501 by QUICK 861DW hot air rework station, and then measure it again, the data is normal now.

Install the iPhone Nand flash back to iPhone motherboard, and then assemble the iPhone. Test the iPhone by iTunes, no 4014 error. After get into IOS, all functions on iPhone works perfectly.