Off/on button does not work on radio

Are you saying the radio is not saying "CODE" or something like that after losing battery power? It does nothing at all? If there is no response at all, check for any blown fuses for sure. If nothing else, a power surge could have damaged the radio, and a local dealership or original equipment audio repair facility near you will be needed to help repair it. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops