1

00:00:00,633 --> 00:00:03,533

In this video we're going to learn about the baseband chips

2

00:00:04,866 --> 00:00:08,600

In the iPhone mainboard, the baseband chip is a read-write ROM chip,

3

00:00:08,900 --> 00:00:12,200

similar to the BIOS chip, which stores some programs

4

00:00:15,200 --> 00:00:17,266

If the program inside is lost,

5

00:00:17,833 --> 00:00:20,700

the phone's ability to make calls cannot be restored

6

00:00:22,766 --> 00:00:25,233

There is only one program for each phone,

7

00:00:25,766 --> 00:00:27,700

and it is tied to the baseband

8

00:00:28,566 --> 00:00:32,533

The baseband chip is similar to the logic chip on early Apple models,

9

00:00:32,766 --> 00:00:34,266

also with four pads

10

00:00:35,633 --> 00:00:37,966

In the real thing we can not distinguish,

11

00:00:38,466 --> 00:00:42,200

we can only identify by the component map or circuit diagram

12

00:00:43,233 --> 00:00:45,633

The program in the baseband chip can be read

13

00:00:46,733 --> 00:00:50,000

If this chip has a crack, or a broken edge

14

00:00:51,166 --> 00:00:53,466

We can read out the program inside the chip,

15

00:00:54,033 --> 00:00:56,166

and then write to other baseband chip,

16

00:00:57,566 --> 00:00:59,400

it can also be used normally

17

00:01:00,000 --> 00:01:03,300

But if the chip is damaged and the program cannot be read,

18

00:01:03,966 --> 00:01:05,766

the machine cannot be repaired

19

00:01:06,866 --> 00:01:09,800

When replacing the chip after the program is read out,

20

00:01:10,033 --> 00:01:12,366

we need to consider the capacity of the chip

21

00:01:12,666 --> 00:01:15,433

Only the chip with the same capacity can be replaced

22

00:01:16,733 --> 00:01:19,433

Let's go to the mainboard to identify the baseband chip

23

00:01:21,400 --> 00:01:23,666

The mainboard is an iPhone 7 mainboard,

24

00:01:24,033 --> 00:01:28,033

and its baseband chip is in the lower left corner of the baseband power supply

25

00:01:28,600 --> 00:01:31,600

The baseband chip is about the same size as the logic chip,

26

00:01:32,100 --> 00:01:35,166

and both are very small, with only four pads

27

00:01:35,866 --> 00:01:39,333

This chip is called a baseband chip, and it's very small

28

00:01:41,800 --> 00:01:43,966

The mainboard is an iPhone 8 mainboard,

29

00:01:44,266 --> 00:01:47,466

and its baseband chip is located to the left of the baseband

30

00:01:49,433 --> 00:01:53,533

As you can see, the iPhone 8's baseband chip is also very small

31

00:01:54,900 --> 00:01:57,033

This mainboard is a XR mainboard,

32

00:01:57,566 --> 00:02:01,300

and its baseband chip is located in the lower right corner of the baseband

33

00:02:01,833 --> 00:02:04,400

This very small chip is called a baseband chip

34

00:02:05,800 --> 00:02:08,966

Baseband chips store programs that are bound to baseband

35

00:02:10,633 --> 00:02:14,133

If the baseband chip is damaged and the program cannot be read,

36

00:02:14,466 --> 00:02:17,366

the phone's ability to make calls cannot be repaired

37

00:02:17,866 --> 00:02:19,700

So that's it for this lesson