The ASUS B85M-F fan is always running, the light is not lit, the BIOS is brushed, the PQ804 is removed and replaced with a new one, but the fault is still the same, so the PQ801 is removed and connected to the PQ800 through a 10K resistor, and the PQ800 is replaced with a new one, and the fault returns to normal.
iPhone 12 can't connect WiFi. Use a polishing pen to polish the middle layer pad, plant tin in the middle layer, and fix the fault.
0.65mA should be that the CPU didn't come up. After checking, it was found that the two capacitors behind the CPU were broken. Replace two 330U capacitors, make sure that there is no error in power-on test, and the current goes up to 1.26. Turn off the machine, connect the screen, and turn on the machine.
Asus ASUS H110 CPU has no voltage, replacing 358 is invalid, replacing PQ801, troubleshooting.
The measured VR_EN of the power supply chip only fluctuates between 2.9V and 3.2V, and it is obvious that there is a problem along the way. It is measured that the PG signal of memory power supply of 2 pins is abnormal; After the small tube is replaced, the power will not be cut off, and the voltage will return to normal.
After the heavy fall of OPPO Reno Ace, the screen broke into a spider's web, and the screen was turned on black. After replacing the display, the fault was repaired.
The ASUS H110-F does not display when it is powered on, and the fault remains after the CPU power supply chip is removed. After the chip UP1540P is replaced, the fault is repaired.
After checking, there is an indicator light on the inserted charger, and there is no boot response when the power-on key is pressed, but the indicator light will go out when the power-on key is pressed, which may trigger protection due to local short circuit. It is found that many capacitors are short-circuited. After removing the short-circuited capacitors, test the other capacitors to ensure that they are not short-circuited. After commissioning, 3.3V returns to normal.
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.
