Radio Problem

I have a 1993 900 S Hatchback, and I love the car, but for some reason the radio won't play. I've removed the radio and put it back in, entered the correct code, and it just goes to a preset station, and the digits just keep blinking as well as the preset station number. The antenna has gone up, and it seems like the radio should work, but it just keeps blinking instead. Anybody have any ideas? Thank you very much in advance