Schematic in PDF format for the H54Y board, UMA variant, meaning integrated graphics with no discrete GPU, packed in a ZIP of about 1.20 MB. The name gives no laptop brand or revision, so check the board code and revision silkscreened on the PCB. Repair technicians use such a diagram to trace power rails and sequencing, check charger and VRM circuits, read component values and follow signals to the EC and SPI flash. Discrete-GPU versions of the same board may differ in their circuitry.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.