The 5LN02N part is covered by this 41.5 KB PDF, indexed as a schematic but most likely a component datasheet. Nothing else is stated in the name; LN in this family seems to denote an N-channel small-signal MOSFET and the N suffix a package version. It helps with pin identification, on-resistance and voltage limits when a low-side switch or level shifter is suspected. Compare the case outline with the footprint on the PCB, because suffix variants are not interchangeable physically.
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.