When reinstalling the PFD or the MFD, refer to the aircraft installation guides for the pin connectors. Assuming the connectors on a replaced or repaired unit are incorrect, will delay your re-installation of the unit and delivery back to the pilot. 

For example, Connector J731 is on the back side of the PFD in this PA32 drawing, and does not connect to the far right side of the PFD (J730). 

Piper 
772-299-2643
Derwin (Spin)