Schematic PDF named only T135, around 768 KB, with no brand listed. It may relate to the Toshiba Satellite T135, but the name alone cannot confirm that, nor any board number or revision, so open the title block to identify the design and compare it with the markings on your PCB. Once matched, a schematic like this is used to trace power rails, check regulator outputs, follow signal paths and find the parts involved in a short or no-boot fault. Any PDF reader opens it.
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 .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.