I would speculate that such a case of sudden death (with no sound) would be the result of a blown fuse/circuit breaker, a wire that has become disconnected or a broken wire.
It does not sound as if there is a mechanical problem and, if so, you should be able to manually extend the slide. If you can, that should eliminate one potential problem area.
Happy Camping! ///// Richard D.
2006 4x4 Ford 250 SD / 2007 Flagstaff 827 FLS
One very patient wife and one furry child who travels with us. Forty-two years of trailering and camping, and I still have a blast.