iPhone 12 Pro Max shows no service and no signal.

Machine model: iPhone 12 Pro Max

Malfunction: iPhone 12 Pro Max shows no service and no signal.

Maintenance process: after receiving the customer’s mobile phone, it is found that the mobile phone shows no service when it is turned on, and it is found that there is no baseband when the setting test is turned on.

iPhone 12 Pro Max shows no service and no signal figure 1.

After disassembling the machine, it is found that the motherboard has obvious deformation. According to the previous maintenance experience, such machines are generally caused by middle-level virtual welding and dropping points.

After layering, it is found that the upper board has dropped points, make up useful points, clean the pads, and test them with a test rack. When the baseband is found, re-attach the upper and lower boards and put them back into the mobile phone.

iPhone 12 Pro Max shows no service and no signal figure 2.

After the card is plugged into the boot test, the mobile phone recovers the 4G network, can normally connect to WiFi, and the signal of the mobile phone is also strong. The fault is perfectly repaired, and the maintenance is over.