If you cannot obtain the schematic, use these generic steps:

The (often stylized with the Compal manufacturing code prefix "LA-") is a laptop motherboard manufactured by Compal Electronics. Compal is one of the world's largest Original Design Manufacturers (ODMs), producing internal hardware for major global laptop brands. Common Laptop Associations

The power LED turns on for a few seconds and then shuts off or loops continuously.

Integrated Intel HD Graphics, or an optional discrete AMD/NVIDIA GPU configuration (UMA vs. DIS platforms).

Once the power button is pressed, the EC sends wake signals to turn on the rest of the operational power supplies: +1.35V (DDR3L) or +1.2V (DDR4).

[ +19V_VIN (Adapter Input) ] │ ├──► [ +3VALW / +5VALW (Always-On Standby Power) ] │ │ │ └──► Powering EC / Super I/O (KB9022Q) │ └──► [ Power Button Pressed ] │ └──► [ +1.35V_VCCST / +1.35V (DDR3L RAM Power) ] │ └──► [ +1.0V_PCH / +0.95V_VCCIO ] │ └──► [ +VCC_CORE / +VCC_GT (CPU/GPU Power) ] 1. Primary Input Rail ( +19V_VIN )

Complex multi-phase voltage regulation modules (VRMs) stepping down the primary 19V DC-in rail to CPU, RAM, and system logic voltages. Anatomy of the LA-C921P Schematic

If you are dealing with a heavily damaged board, look out for a bundled ( .cad , .brd , or .fz format). A Boardview allows you to visually click on any pin on a digital 3D model of the motherboard to see exactly where that trace runs, which complements the schematic perfectly when repairing broken traces or identifying burnt, unreadable components.

To help find the exact variant or matching boardview files for your repair, let me know: