Using the schematic, locate +VIN (19V). Probe PAD101 . If it’s 0V, check PD101 (protection diode).
If you manage to obtain the schematic diagram, here is the guide on how to interpret the critical sections: laj641p schematic 2021
Like many gaming laptops of this era, typical failures involve power rail shorts (often 19V) or charging circuit malfunctions. Using the schematic, locate +VIN (19V)