Compal LA-E541P (used in HP 15-bs000 series) Key ICs:
If voltage is missing here, the charging IC is likely in protection mode due to a short circuit down the line. Finding a Short Circuit to Ground lqv77 laptop schematics
If you provide a valid board code, I can generate a like this: Compal LA-E541P (used in HP 15-bs000 series) Key
Laptops do not turn on all at once; they follow a strict chronological power sequence. The EC chip powers up via +3VALW . The EC reads the BIOS firmware. The power button is pressed, sending a signal to the EC. The EC reads the BIOS firmware
Tracks power distribution from the DC jack to the CPU and RAM.
Since lqv77.com can be difficult to use and may not always be online, knowing several reliable alternative sources is critical for any repair technician.
The schematic reveals that ENABKL (Backlight Enable) comes from pin 23 of the Embedded Controller (EC - IT8226VG). If that pin is stuck low, the backlight will never turn on, even though the image is present.