you still need to prep it for takeoff, flap settings, fmc programing, fuel pumps, window heat as required stab trim settings...all those kinds of goodies..do you still have blank gauges after irs alignment?...maybe you need to go through the pre-flight checklist line by line, you'll find it somewhere in the forum if you do a search...there is a very good tutorial on youtube by one of our very own member, Bob Markey which is at the top sticky forums