Datasheet in PDF form for a part marked C4581. The name gives only this code, which may be an abbreviated transistor marking, so check the document header to confirm the exact device. Datasheets like this list the pin assignment, maximum ratings, package outline and electrical characteristics. Use it to verify a suspect component, pick an equivalent replacement, or confirm the orientation before soldering. It is 184 KB and opens in any standard PDF viewer.
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 @datasheets0. Enginerys does not host this file.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.
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