radio problem on 03 accord?
 

i recently bought 03 accord ex and the radio is not working. the display does turn on and the time keeps flashing on the screen. The battery was also recently replaced. could it be that i need a radio code?...when i tried pressing 1 and 6 for code nothing happens. The car also has pioneer dvd player installed which works just fine. Could this be the reason for the radio to be not working? plz helpany help would greatly be appreciated. thanks