Schematic in PDF format identified only as AB540, in a 1.47 MB ZIP archive. The name gives no brand, device type or revision, so confirm the code against the markings on the board itself. Once matched, the schematic shows the power rails, signal paths and component references needed to trace faults and check for shorts. Extract the ZIP and open the PDF in any reader, and treat page references cautiously until the board identity is confirmed.
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 @schematicslaptop. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip