Solved: Error -1 and always keep DFU mode on iPhone 6S

The iPhone 6S has -1 error and always keep DFU mode,  we can't get into IOS system smoothly. In a word, the iPhone 6S can't used at all, how to solve it? 

First Step

Disassemble the iPhone 6S by phone opening tools, and then connect iPhone motherboard with DC power supply, the current is 100mA. 

Second Step

Test the power supply of iPhone Nand flash by DC power supply , the iPhone Nand flash on the left side of the capacitor can be tested to 0.9V, 1.8V, 3.0V, the power supply is normal

Third Step

Removeing the iPhone Nand flash to test. First, hit the resistance value, and it is normal. Test the iPhone nand flash by using the iPhone test fixture. This 6S original Nand flash is damaged, the data can only be read but only replaced.

Fourth Step

Query the serial number through IMEI. The professional of sn with BT WF address can find out the Bluetooth and WiFi address (referred to as the three codes). After the mobile phone is replaced, the mobile phone after win 11 must be written to the original three codes to activate after replacing the nand flash.

Before writing the code, write the underlying data of the corresponding model first. If the underlying data has any problems, there will be some strange problems, which belongs to the underlying error phenomenon. So you can use JC PCIE  NAND test fixture to read and write. After watching the camera, the screen is reversed. Re-writing the underlying data to solve the problems

Final Step






After re-writing the data, install the iPhone 6S and test it. Flash the iPhone, it flash process bar goes successfully, there is no unknown error appears. Turn on the iPhone, the iPhone is entering the IOS system smoothly. The problem has been solved!