Labelled SDNS035E, this 189 KB PDF is a datasheet whose letter suffix most likely indicates the fifth revision of the document. The device itself is not named, so read the header to identify it. Once you know the part, the pinout and electrical specifications let you measure the chip in place, check that its inputs and supplies are present, and confirm whether a replacement from another source shares the same package and ratings.
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 @datasheet_technar_org. 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)