1992--no radio

I have a 1992 K2500 that sat long enough for battery to discharge (about a year) Put new battery in and radio doesn't work. Stuck on 98.1 FM or 1:00. Can't move time or station setting, but can work fade/balance settings. It is the digital style found in the Silverados--Thanks

You will probably need to have the radio repaired (replaced). There are two parts to the radio, the Radio head that you see in the dash and a second part under the dash by the steering column, guess that is the actual reciever.
Mine did basically the same thing and had it fixed for about $70. You might find one on ebay or some place a little cheaper.