Listed as a schematic, this 75.9 KB PDF named 31DQ03 is better understood as a component document: the code follows a diode part-number pattern. No device or board is given in the name. Use it as a reference for the electrical limits, thermal data and package drawing of that part when diagnosing a shorted or open rectifier with a multimeter in diode mode. Always compare the printed marking and suffix on the suspect part to this designation, since the 03, 05 and 09 variants are not interchangeable in every circuit.
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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