If your radio was dropped -- or even if it wasn't -- it might have a cracked or cold solder joint which magically started conducting again after being moved & jostled one more time.
Some times, when a "working" radio has been sitting unused for years, all it takes is using it for a while to wipe the corrosion/gunk off the bandswitches and other controls, to make it come back to life.
Restored radios that are used on a regular basis will last longer than those which sit in storage for years. Same as an old car, sewing machine, clock, or whatever.
If you ever get in the mood to throw something else like an SX-100 in the dump, contact me first :-)
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html