1

00:00:00,266 --> 00:00:02,300

iPhone connection circuit repairing

2

00:00:02,900 --> 00:00:08,266

This video mainly explains the working principle of the connection circuit of iPhone 7 to iPhone X models

3

00:00:09,800 --> 00:00:13,800

Working principle step 1, after the iPhone is triggered,

4

00:00:14,166 --> 00:00:18,866

the main power supply will provide 1.8V and 3.0V power supply for the USB chip

5

00:00:18,866 --> 00:00:20,866

after receiving the power-on signal

6

00:00:21,433 --> 00:00:27,800

Step 2, after the CPU works normally, it will detect the USB chip through the I2C bus,

7

00:00:28,100 --> 00:00:31,300

and the iPhone will enter the system after the detection is passed.

8

00:00:31,933 --> 00:00:37,100

Step 3, when copying the iPhone data, we plug in the data cable,

9

00:00:37,866 --> 00:00:43,566

and the data cable insertion detection signal DETECT will be sent to the USB chip through the charging connector

10

00:00:43,700 --> 00:00:47,833

Step 4, after the USB chip receives the DETECT signal,

11

00:00:48,200 --> 00:00:52,366

it will send the data line ID identification signal to the main power supply

12

00:00:53,233 --> 00:00:57,400

Step 5, after the main power supply receives the ID signal,

13

00:00:57,700 --> 00:01:00,600

it will send an identification signal to the CPU

14

00:01:01,466 --> 00:01:05,366

The CPU controls the ACC power supply chip through the I2C bus

15

00:01:05,466 --> 00:01:09,066

to generate ACC power supply and send it to the USB chip

16

00:01:10,466 --> 00:01:14,500

Step 6, after the USB chip receives the ACC power supply,

17

00:01:14,833 --> 00:01:18,300

it will convert ACC1 and ACC2 power supplies,

18

00:01:18,500 --> 00:01:21,433

and send them to the data line through the charging connector

19

00:01:22,433 --> 00:01:27,833

ACC1 and ACC2 are the power supply voltages on the front and back of the data line

20

00:01:28,266 --> 00:01:31,766

Step 7, after the data line has power supply,

21

00:01:31,933 --> 00:01:36,066

it will send the verification information of the computer connection to the USB chip

22

00:01:36,066 --> 00:01:38,466

through the DP1 and DP2 buses

23

00:01:38,733 --> 00:01:45,200

Step 8, after the USB chip receives the connection information, it sends an interrupt signal to the CPU

24

00:01:46,533 --> 00:01:50,166

Step 9, after the CPU receives the interrupt signal,

25

00:01:50,333 --> 00:01:53,600

it will read the connection information through the UART bus

26

00:01:54,066 --> 00:01:59,533

After the verification information is read, the "Add Trust" prompt will pop up on the screen

27

00:02:00,566 --> 00:02:05,466

After clicking Trust, it will pop up a prompt to enter the screen unlock password

28

00:02:06,066 --> 00:02:10,500

When we enter the password, the iPhone and computer can establish a connection

29

00:02:11,300 --> 00:02:14,566

Step 10, when copying data on the computer,

30

00:02:14,966 --> 00:02:20,166

the CPU will read the data stored in the hard disk and send it to the USB chip through the USB bus

31

00:02:21,266 --> 00:02:25,066

Step 11, after the USB chip receives the data,

32

00:02:25,300 --> 00:02:29,000

it sends it to the data line through the DP1 and DP2 buses,

33

00:02:29,266 --> 00:02:31,466

and then sends it to the computer

34

00:02:32,166 --> 00:02:36,733

At this time, the progress of copying data will be displayed on the computer

35

00:02:37,466 --> 00:02:43,166

If there is no response when we plug in the data cable, it means that the connection circuit is faulty

36

00:02:43,533 --> 00:02:46,100

First, we can replace the USB chip

37

00:02:46,666 --> 00:02:51,533

If it is still not normal after replacement, we check the working conditions of the USB chip

38

00:02:51,966 --> 00:02:53,700

That's all for this video