The 2SC3087 is the subject of this 93.1 KB PDF, listed among schematics. No maker, package or revision appears in the name. Per the Japanese JIS standard, the 2SC prefix denotes an NPN bipolar transistor of the high-frequency type. Repair work usually draws on such a sheet for terminal identification and maximum voltage and current values, plus gain ranges when matching a replacement. It opens in any PDF reader, but check that the device on the board carries this exact code first.
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.