For LCD panels, the BM5291 often integrates or controls a multi-output power supply:

If you are currently working on a BM5291 board, these professional resource hubs often host the schematics and boardview files needed for a successful repair: BIOS ARCHIVE - Laptop Firmware & Tools

The BM5291 schematic serves as a comprehensive map of the laptop's internal hardware. Key sections of the document include: System Block Diagram