Schematic PDF of 6.18 MB with the code-style name la19c350d1, which gives no clear brand or device model. The la19 prefix resembles some LCD TV or monitor main board codes, but this cannot be confirmed from the name alone, so open the document and read its title block. Once identified, a schematic like this shows power supply stages, signal paths and part values for fault tracing. Compare the board number on the drawing with the one printed on your PCB before use.
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 @pdf_servicemanual. 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.