i have a 2008 honda accord coupe and i recently changed the batter after i did my car radio/cd player is no longer playing sound this is after i put in the code for the radio im not sure why it shows the cd playing and the track timing down but it does not play any sound help! plz and ty!!

ok so i found out before i change the battery my dad tried to boost it and he put the connectercs to boost on wrong ends -.- so im guessing he blew out the radio does this mean i have to get a whole new system or is it easy to fix?? and what would be estimated cost to get it done or could do it myself??