If you are getting NO reception at all , then I would suggest that the aerial isn`t connected.
If it is a push-in connection, make sure that it does connect properly. ( If necessary test your aerial by using an extra length of wire to temporarily connect aerial to radio to prove aerial OK )
I`ve had the situation where a replacement radio (of a different make) with identical connecting sockets at the rear was , when measured with a ruler , physically 1 cm shorter . The battery supply socket fitted OK but the aerial socket on the opposite corner didn`t fit properly. The socket had to be modified (extended) to fit tightly.
RegWorts, June 2008