The 2SC1755 is covered by this 53.2 KB PDF, which the index lists as a schematic although the name refers to one component. Under the Japanese JIS scheme, 2SC parts are NPN bipolar transistors, making the file most likely a manufacturer datasheet. Repair use includes confirming pin order before desoldering, reading collector voltage and dissipation limits, and checking gain classes for matched replacements. Inspect the part on the board for suffix letters or a different package before relying on these figures.
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.