Dell G7 7588 notebook Won't Turn On repair

Dell G7 7588 notebook Won’t Turn On repair

Machine model: Dell G7 7588 notebook

Motherboard board number: LA-E993P 1.0

Symptom: Notebook Won’t Turn On

Repair process:
I received a Dell G7 7588 laptop. The fault description is that after changing the screen with a high frequency of 144hz, it took a day to use the Won’t Turn On. There is no water damage in the visual inspection, and the customer has dismantled it and cleaned the dust once.
Disassemble the machine and visually inspect the place where the motherboard is not burned. It is measured that there is no 5V in standby and only 0.26 in standby 3V,Diode value is normal, indicating that the CPU and the bridge are not broken, and it is judged that it is the standby chip or VCC is pulled down or short-circuit current.

Dell G7 7588 notebook Won’t Turn On repair Figure 1.
Open the drawing to find the corresponding number PU100 standby chip SY8286, 11 pin EN 1V only does not have VCC, check schematic to know that two resistors and one Capacitor are connected in front of the EC, and the Capacitor is still the same without VCC.
The measurement found that there is no VCC on the side of PR102 on the ground, and 1V on the PCH connected to EC11 on the side of PR103.pin is 0V. The magnifying glass checks that there is no deterioration of corrode. Replace it with a 100K generation. Re-test the standby 3V and it has come out. Normal 3.3V, 5V is not. Next, repair the 5V standby. Look for the same model of the 5V standby chip PU18V00 from the new drawing, the problem is still this 11 pin problem. 11 The resistor connected to pin is 47K, which normally appears after replacement 1.

Dell G7 7588 notebook Won’t Turn On repair Figure 2.
After the replacement, 0.09 appears in normal standby mode, 3V 5V appears in standby mode, normal switch booting up.Nand has been removed by the customer and can only enter the BIOS.booting up only takes 3 seconds after flashing and restarting it twice. After flashing the BIOS, it will boot up. After filling in the relevant information, the booting up will enter the BIOS to set up and boot normally.