IPhone XR falls heavily without baseband, and the card has no signal repair

First, open the annotation diagram of Xinzhizhao software to find the baseband power supply and baseband CPU, and then remove the baseband CPU to replant tin.

Machine model: iPhone XR

Fault phenomenon:

The customer described that his iPhone XR mobile phone was played by children at home, and one fell to the ground without holding it steady. Fortunately, the screen was just a little scratched on the tempered film, and there was nothing wrong with the inner screen and the outer screen. Otherwise, it would be really tearless to change the screen. But the problem came. After the phone fell, there was no network. The customer restarted the phone first, but it still showed that there was no signal.

Maintenance process:

After receiving the customer’s mobile phone, there is no signal after starting the test. The version number of the modem firmware in the mobile phone can’t be seen. In this case, the baseband CPU of the mobile phone is not working, and there is no signal in the mobile phone without baseband.

IPhone XR falls heavily without baseband, and the card has no signal for maintenance. Figure 1

IPhone XR is a single-layer board, and there is no virtual welding in the middle layer when it is dropped. You should drop the baseband power supply or baseband CPU and break it. First, open the annotation diagram of Xinzhi Software to find the baseband power supply and baseband CPU.

IPhone XR falls heavily without baseband, and the card has no signal for maintenance. Figure 2

Disassemble the mobile phone, and find the baseband power supply and baseband CPU of the motherboard according to Xin Zhizao’s label. All the power supply of the baseband power supply is normal, so I replanted the baseband power supply to prevent the baseband power supply from being soldered, and the fault remains after replanting. Only the baseband CPU can be redone, and the baseband CPU can be removed and replanted.

Solder the baseband CPU, put the motherboard back into the machine for testing, and the signal of the boot phone is normal, and the fault is repaired.