Covering the 2SC3811, this 45.7 KB PDF has an _E suffix in its name, which is not explained and may denote an edition or English version. JIS numbering uses the 2SC prefix for NPN bipolar transistors, so the document is best treated as a datasheet. Look up pin functions, absolute maximum voltage and current, gain classes and package dimensions when diagnosing or replacing the part. Any PDF viewer opens it. Check the marking on the PCB component matches before trusting the data.
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.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.