RV Repair: 12 volt electrical, pop up camper, volt system

Question
I have a 2006 Rockwood 2290 pop up camper.  We just got back from a trip and everything worked fine.  Now that we are home and I set it up to clean it out the 12 volt system does not work.  I charged the battery (which was low or dead) but still no 12 volt power.  I plugged in to 120 volt and everything works.  When I unplug the 120 volt I have no 12 volt.  I checked all of the fuses, all OK.  I checked all lights, fridge etc. and everything was turned off so I can't find anything draining the battery. What else can I check before I take it in to the dealer to have them diagnose? Thanks.

Answer
Sounds like it might be a convertor/invertor problem.
I am sure you are still under warranty, so take it to the dealer and let them worry about it. Or if your dealer is too far away, Rockwood customer service can probably authorize you to take it somewhere locally. Give them a call before you do anything. It may be a real simple fix. Just make sure you "go by the book" so as to not do anything to void your warranty.
Dave