1983 Mercedes Benz 240d Radio

My radio will not turn on anymore. It was working perfectly fine for 2 hours until I attempted to insert a cassette tape/mp3 adapter (cassette tape with a cord coming out of it to attach to mp3's). I inserted such tape, ejected it, turned off the car, turned it on later, radio worked for 2 minutes, then stopped working.

I don't know whether this is solely because the car is old, or if this type of cassette damaged the entire radio, or if I pressed a wrong button, but I am pretty bummed since I just bought it today.

Please help.