Anyone remember the VH-OJM incident?
The 747 has all the avionics in the underfloor area, the A380 has most of it on the upper deck aft of the cockpit, where the height is not enough to place passengers. With two decks of pax and one deck for luggage you need to minimize any space wasted for electronics down there, which in cases like this can save you a fortune... However, the mechanics will have some work to do now...