iPhone 12 can’t connect WiFi

iPhone 12 can’t connect WiFi

Machine model: iPhone 12 

Malfunction: iPhone 12 can’t connect WiFi.

Repair process: After receiving the customer’s mobile phone, it can be connected to the network test when it is turned on, and it can be connected to WiFi normally. It’s stuck to open the APP and network card, and it can’t even be opened.

iPhone 12 can’t connect WiFi Figure 1.

First of all, we know from the customer’s description that the WiFi signal is weak because the machine has been dropped. Priority is given to whether it is caused by virtual soldering of WiFi chip, virtual soldering of antenna connector or virtual soldering of middle layer of motherboard. First disassemble the machine to check that the WiFi antenna connector is not loose, and exclude the external connector.

As the WiFi chip is on the lower board, the main board is directly layered. After layering, it is found that there is virtual welding in the middle of the main board, and all the solder joints have been oxidized. Use a polishing pen to polish the middle pad, and measure the WiFi-related signal points without virtual welding or short circuit. Plant tin in the middle layer, and discover WiFi through the boot test function of Xinzhi test rack.

iPhone 12 can’t connect WiFi Figure 2.

The upper and lower motherboards are bonded and welded, installed and tested, and the mobile phone is turned on normally and connected to WiFi. After testing for a period of time, there are no ups and downs, the fault is perfectly repaired, and the repair is over.