Huawei Nova7 screen shows abnormal repair

Huawei Nova7 screen shows abnormal repair

Machine model: Huawei Nova7
Customer’s description: The mobile phone has been in the water for a while, and suddenly Blurred screen appears on the screen.
Malfunction: the display of the mobile phone screen is abnormal.
Actual measurement results: All functions of the mobile phone can be used normally, only Blurred screen appears on the screen.
Fault analysis: Because the customer’s mobile phone was slightly water damage, all functions can be used normally, focusing on the fault on the screen, or the screen abnormality caused by the partial fault of the display signal.

Huawei Nova7 screen shows abnormal repair figure 1.

First, replace the screen for testing. If the screen can display normally, it is a screen problem. If the fault continues, it is the motherboard display circuit problem. Many friends don’t necessarily have a test screen in their hands, so directly measure whether the pin bits of BTB connector display screen diode value are normal or not. If it is abnormal, the fault must be on the circuit connected with the abnormal pin bit. If it is normal, please replace the screen directly.
In this case, after changing the screen, the fault remains. Next, open the Xinzhizao Soft drawing software and find the display BTB connector.

Huawei Nova7 screen shows abnormal repair figure 2.

OverLoad easuring each pin bit diode value, the 4th pin diode value OverLoad 6901 under BTB connector is found, which proves that this line has been disconnected.

Huawei Nova7 screen shows abnormal repair figure 3.

Look, this line is the MIPI signal line of the display screen, with one end connected to the display screen and the other end connected to the CPU through a resistor.

Huawei Nova7 screen shows abnormal repair figure 4.

After checking, the circuit from BTB connector to resistor has been disconnected by corrode, so it is ok to repair the circuit. At this point, the Blurred screen fault of Huawei Nova7 was suddenly repaired.