PDF schematic, 1.16 MB, named Tin Yat 80A; the name gives no brand, device type or board number, so the target hardware must be confirmed from the drawing itself. Read the title block and compare it with the markings on the board before use. A circuit diagram like this lets a technician follow supply rails and signal paths, identify component values, and locate the source of a short or failed stage. It opens in any standard PDF viewer, with searchable text if the drawing was exported from CAD.
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 @alischematics. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.