While scanning, does it say ID SCAN or ID SEARCH? If so, you should be getting something. Press SCAN while it is scanning until it says ID SEARCH, that will allow any talk group. Press hold and see if you get the control channel you think you should be getting, and also do you get an indication on the signal strength indicator? That will tell you at least that you have a signal. Cross check the db list for control channel frequencies vs what is in your file. Do you have talk groups programmed.
Hopefully, someone has a 996 file. I have a file or 2 for my 396 using ARC 396 but I don't think it works on yours.