Huawei nova9 A9 turns on the bright logo and automatically restarts (the battery detection pin is disconnected)

Huawei nova9 A9 turns on the bright logo and automatically restarts (the battery detection pin is disconnected).

Huawei nova9 A9 turns on the bright logo and automatically restarts, and maintenance is found.mobile phoneThe resistance on the back of the battery is OL, which means that the wire is broken. We flew the wire directly, and after testing, we found that the mobile phone was turned on normally. How exactly is it repaired? Please see below:

[Machine model] Huawei nova9 A9

[Fault phenomenon] logo automatically restarts when the machine is turned on.

[Maintenance process] I received a machine sent by a customer for repair, the model is Huawei nova9 A9, and the customer described it as automatic restart when the logo is turned on.

After receiving the machine, we first turn it on to test whether the fault is true. Pressing the power-on button can light Huawei’s logo, but it will automatically turn off soon, and it will not be restarted. If we can’t get into Huawei’s logo interface, we must first find out whether it is automatic restart or automatic shutdown. There is a big difference between these two. For automatic restart, we will generally consider system damage, font, CPU virtual welding damage or inductance virtual welding. For automatic shutdown, we will generally only consider battery or battery detection pin problems.

This machine is automatically turned off, so let’s just check whether there is anything wrong with the battery or the battery detection pin. When measuring the battery holder, it is found that the resistance of the battery detection pin is basically there, but one resistance is low.blueprint There are more than 700 in the circuit, but the measured resistance is only more than 300, which is definitely abnormal. Looking at this line, I found that all the way is on the back and all the way is on the front. It is normal to measure the front line, but the resistance value of this line to the back is OL, indicating that this line has been disconnected from the back.

Huawei nova9 A9 turns on the bright logo and automatically restarts Figure 1.

Huawei nova9 A9 turns on the bright logo and automatically restarts Figure 2.

We flew directly to the root line, and then started the test, and found that the mobile phone was turned on, which means that the bright logo was turned off due to the open circuit of the battery detection pin. Fix the flying wire with green oil and directly enter the system to test the function.

Huawei nova9 A9 turns on the bright logo and automatically restarts Figure 3.

[Maintenance result] Install the motherboard into the mobile phone, and start the test. The mobile phone is normally booted into the system, and the functions such as charging, WiFi, voice, compass, vibration and telephone are normal. The maintenance is over here.