Here the 2SK1234 N-channel field-effect transistor is described in a 46.1 KB PDF. The 2SK code marks it as an N-channel device under the Japanese JIS scheme, used in power switching and amplifier circuits. Since the file name lists no package or maker, confirm those from the part body. The sheet should provide ratings, threshold, on-resistance and pinout, which a technician uses to test the transistor correctly and to choose a replacement that will handle the same load safely.
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.