93 2500 radio problum

[harleypanrider]

recently my radio qwit when i hit power button it powers up but none of the buttons have any afect when you push them tape player either i didnt see anything in fuse block marked radio one fuse said rdo but they all tested good is there another fuse for this somewhere or does anybody have any other ideas where trouble might be i dont have a book for this so not sure what to atemp next