Part documentation for the 2SC5266A in PDF form, 182 KB, listed among schematics. JIS numbering makes 2SC an NPN bipolar transistor, while the A suffix generally indicates a revised or uprated version of the base 2SC5266, so the two should not be assumed identical. Use it to confirm terminal order, case style and electrical limits before fitting a replacement. Checking the exact suffix printed on the original device matters here, because ratings or packaging can differ between lettered versions of the same number.
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.