WiFi chip has been repaired at home. The power supply of the WiFi chip is normal when it is turned on, so the iron case of the crystal oscillator is directly found. After disassembling it, the crystal oscillator is taken down to measure the ground value of the crystal oscillator, and it is found that the two ground wires of the crystal oscillator are dropped. Find a good 38.4MHz crystal oscillator and put the motherboard back inside the phone.
Measuring the resistance value of one end of C1226 main power supply is also about 400, basically locking the main power supply or middle layer virtual welding. Welding the main power supply in layers. Start-up test, there is a signal, and the maintenance is over.
HUAWEI Mate 30 can't connect WiFi. Clean the corroded place first, then replace the WiFi chip and fix the fault.
HUAWEI Mate 30 has low boot brightness, and the screen is black when fast-forwarding the system. When disassembling the machine, it is found that the board layer is broken, and it is directly repaired by flying the wire.
HUAWEI Mate 30 can't be turned on, the CPU is damaged, and the fault is repaired after redoing the CPU.
HUAWEI Mate 30 has no ringtonel. Remove the upper board, replant the tin, and fix the fault.
HUAWEI Mate 30 has no sound after connecting Bluetooth. After making up the phone, the WiFi chip is replaced, and the fault is fixed.
After HUAWEI Mate 30 mobile phone Won't Turn On and Current heating test, it was found that coder and power amplifier chip were damaged. Replace coder chip and repair the fault.
Huawei Mate 30 mobile phone Won't Turn On, the power chip does not work properly, after the chip is Repeat welding, the fault is repaired.