There is a fuse panel at the end of the dash under a cover visible with the driver's door open. The underside of the cover lists what each fuse protects. You owner's manual also has this information. You can check the fuses there.
You might try disconnecting the battery for a few minutes. That might reset the brain in the radio. If that doesn't work, it's probably time to replace it.
I was able to find a radio on eBay for my '01. You could get lucky.