Datasheet PDF, 64.6 KB, for the KA7500B, a PWM control IC from the KA7500 series and a TL494-style design widely found in computer power supplies. Filed under schematics, it should list the pinout, error amplifiers, oscillator timing and output configuration. Technicians open it in any PDF reader to check the 5 V reference, the sawtooth on the timing pin and the gate drive outputs when a PSU is dead or cycling. A separate KA7500C document exists, so compare the suffix on the chip before relying on specific figures.
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.