The 2SA1898 is documented in this 97.7 KB PDF. Only the part number appears in the name, so although it is labelled a schematic, treat it as the datasheet. In JIS numbering a 2SA code denotes a PNP bipolar transistor. Practical uses include confirming pinout for in-circuit diode tests, reading the collector-emitter voltage and current limits, and checking the package outline when sourcing a replacement. Verify the marking on the failed part and choose an equivalent with equal or better ratings.
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.