How i fix this PSPICE orCAD problem? - Model D1N747 used by D_D1 is undefined
First of all the root part number is 1N747, not D1N747. It is a 3.6 volt 500 mW zener in a glass case. I searched several sites and it is embedded in a long list of part numbers starting with 1N746. OrCAD may not have a dedicated path to that part number.

Also since I have UltraLibrarian it was not part of the ULO inventory. It may require a trace to a manufacture who offers Pspice data. I have version 17.2.0 64 bit and I cannot find it either. You may need to find a similar part that has Pspice data.