PDF datasheet for the MPSA64, a PNP Darlington transistor that the name lists at -30 V and 800 mA. It is typically used as a high-gain switch or amplifier in through-hole designs such as control boards, audio gear and power supply sensing circuits. Technicians check the sheet for the TO-92 pin order, gain figures and saturation voltage before fitting a replacement, since pinouts of similar-looking parts vary between makers. Test the suspected device out of circuit and compare against the MPSA14 or other complements only after checking 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.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.