Any have any ideas how to fix this problem?After I start the APU & switch turns on the APU generator bus switches all the displays (PFD, ND etc) go black in a minute or so. This problem began when I tried to start the plane from a cold & dark cockpit which I obtained by opening another plane first, a Cessna 172, & shutting down its engine & electronics - as per a suggestion from another posting - since then, nothing but problems. And I tried to reverse the procedure but the problem remains. Help

I believe this is an FS9 bug where the battery on heavy jets drain too quickly. Since you're using FSUIPC, go into its settings and check off the option that fixes this.

I found another thread dealing with this problem and took the advice of purchasing & registring FSUIPC - this seems to have taken care of the problem.