Small 27.4 KB PDF named after the part code 5LN01C, indexed as a schematic though it reads like a discrete-component datasheet. The name alone does not describe the device; the LN letters in this series appear to mark the N-channel MOSFET variant and the trailing letter likely denotes the package. Use the document to verify pinout, gate threshold and maximum ratings before testing or replacing the part. Compare the board footprint with the package drawing inside, since suffix letters often mean different cases.
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.