The Sargent cams listed below work for all applications except 16 inside and 50 outside. The equivalent Sargent cam is the 13-0660.
Use the B520-736 for modular cylinder lengths of 1 1/8",...
Von Duprin KR (key removable) mullions requires a 1-1/8" or 1-1/4" mortise cylinder with the standard straight cam, the cam is not inverted. Please see chart below for part numbers.
The keycam may have failed, example here, the latest design keycam can be easily identified as the colored changed to black.
Replace either the keycam or chassis as needed...
This could also happen if the tailpiece isn't installed in a KIL, FSIC, or SFIC cylinder. The FSIC driver also could have come loose from the core in the spindle.
The Schlage ND75 and ND95 locks require the chassis to be assembled and timed correctly for operation. If the chassis has to be disassembled for any reason please refer to the Assembling Schlage ...