Part reference for the 2SA1708, saved as a 154 KB PDF. No device, brand or board number is present in the name, only the component designation. The 2SA code from Japanese JIS numbering belongs to PNP bipolar transistors, so the document should be a manufacturer specification sheet. Use it when you find this marking on a failed stage: read the pin arrangement, check maximum ratings against the supply voltage in the circuit, and look at the package drawing to confirm footprint compatibility for any replacement you intend to fit.
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.