Schematic in PDF, about 420 KB, named only SEM2105, so the name does not identify a laptop model or board number. It may be a datasheet or circuit diagram tied to a part or design labelled SEM2105; open it to confirm what it covers. Schematics like this are used to trace power rails, follow signals and check component values while diagnosing faults. Match any board number or revision shown in the document to the hardware in hand before relying on 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 @iranianRefix. 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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)