need help setting up faders on Performer 3

CenterStages

We have a Performer 3 that was originally set up with two cards and two 16 channel stage boxes, We have just replaced one 16 channel stage box with a 32 channel stage box. I reset the console to factory default and I only have 64 channels showing in the dropdown for fader set up.I f I go to Inputs and scroll down to Input Patch, I can see all the inputs in the new 32 channel stage box in slot 2, however I can not set up the faders that are blank and unused... Help