HUAWEI P40 Pro has poor Bluetooth signal, how to solve it?

Machine model: HUAWEI P40 Pro

Malfunction: The customer described that HUAWEI P40 Pro’s Bluetooth signal is weak, and it can’t be connected to the Bluetooth device.

Maintenance process: After getting the mobile phone, turn it on and turn on the Bluetooth switch for testing. Only 2 Bluetooth devices can be searched. It is found that there are 7 or 8 Bluetooth devices in normal mobile phone testing.

HUAWEI P40 Pro has poor Bluetooth signal Figure 1.

This kind of failure is often caused by the problem of Bluetooth antenna channel or WiFi chip. Check the schematic diagram, find the location of the WiFi chip, and find the BT Bluetooth antenna signal through U7303 chip on the schematic diagram. It is known that the BT Bluetooth antenna signal is the same as the WiFi 2.4G antenna signal.

HUAWEI P40 Pro has poor Bluetooth signal Figure 2.

HUAWEI P40 Pro has poor Bluetooth signal Figure 3.

Turn on the WiFi test again and find that the 2.4G signal is also weak. Therefore, it is judged that the antenna channel filter is damaged. Turn off the signal input inductor L7349 of the 12-pin antenna of U7303 chip, connect one pin of U7303 from L7349, and connect it directly to the antenna pedestal C7301 to make a false antenna.

HUAWEI P40 Pro has poor Bluetooth signal Figure 4.

HUAWEI P40 Pro has poor Bluetooth signal Figure 5.

Put the motherboard back in the case, boot up and test Huawei P40 Pro. Like other normal mobile phones, you can search for several available Bluetooth devices, and the fault is perfectly repaired.