Hello Mark
I come back to Cold and Dark, it actually doesn't work, I do exactly what you told me to do. And each time the plane load with the Battery ON

I open the CDU (SHIFT + 6)> Menu button> Setup> Options> Next Page button> turn on LOAD DEFAULT PANEL STATE !!!! But it turns ON, but the “exec” key of the CDU is lit but does not work ... has no effect

So always with the battery ON without APU and Ext Power
No Cold and Dark,     :-/ :'( :-[
Rgds