Audio Systems: Car Audio, car radio repair, radio repair shop

Question
I have a 2002 SuperCharged Nissan Xterra.  A few months ago my 12 disc,
after market, cd changer decided to stop working.  No big deal, I still have a
single cd player in the dash.  Well it quit working about 2 months ago.  Today
I was driving home, went over a speed bump, heard a loud pop, then the
radio was no longer playing.  Did I seriously blow all speakers at one time!?  
I'm not really concerned about either cd player, but thought you might need
to know a bit of the background story.  
Please help!
Thank you!!

Answer
There are probably some connections that were getting loose from time and vibration.  When you went over the bump it caused the bad connection, maybe the power line, to go open circuit.  If you go over the same bump again it may jar it so that it starts working again!  (Or some similar "bump").

There may be something more sinister going on but you can check it out if you know how to follow the power wiring from the battery to the ignition to the set to see if you lost power to the radio system.

A local car radio repair shop can check it out very quickly - and let you know what is going on.