Compal schematics use an alphanumeric grid system (A-F, 1-8) along the borders of the pages. Use the index at the beginning or end of the schematic document to find components physically on the board via coordinates.
The +3VALW line wakes the Super I/O (Embedded Controller) chip. The EC reads the BIOS firmware and waits for the power button signal. Troubleshooting Common LA-D402P Board Failures 1. No Power / Dead Motherboard (0.00A Power Draw)
If you can tell me the your laptop is showing (e.g., "blinking white light" or "fan spins once then stops"), I can provide more tailored diagnostic steps from the schematic. Share public link
: Often utilizes the SMSC MEC1404 for keyboard control and low-level power management.
Are you trying to fix a specific issue like or a charging problem with this board?
I can guide you through the exact schematic page or component lines to check next. Share public link
Identifying exact component values (resistors, capacitors) after a short circuit.
: Since this board relies on USB-C for power, look for the TPS65982 or similar PD controller section. This area is critical because if the PD controller doesn't "handshake" with the charger, the board won't even receive the 20V needed to start.
: Supports DDR3L low-voltage memory modules.