Unisonic Technologies (UTC) edition of the 2N5401 datasheet, a high-voltage PNP small-signal transistor, kept as a 21.0 KB PDF. UTC is a common supplier of these parts in consumer electronics, so this version suits boards populated with their components. It lists voltage and current limits, gain ranges and the TO-92 style pinout. Use it alongside a multimeter diode test to confirm a suspect part, and compare the pin order with other vendor sheets, since lead arrangements can differ between manufacturers.
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.