Problem TV radio

We have a 2002 Dodge Gran Caravan. Of late we have been experiencing problems with our in-dash radio. It is simply an intermitent off/on problem.turned radio on, OK. Radio already on and turn key on, don't work? Tonight DW had radio on when I was in store, came out turned on key while radio was on and lost radio? Don't know where to start? Any ideas? :

Midwest Dave