2000 Grand Am display back lite on the radio is out but numbers lite up when sun shine on it
 

Hello i had my Grand Am in the shop to have the abs lite on the dash checked out cause it was staying on and i had no brake lites and everytime i put a fuse into the brake lite it would blow as soon as i put it in. So anyway i took it to a reputable shop and the got the abs lite to go out and my brake lites work again but the back lite on my radio is out and i took it back the the shop they tested all the fuses and the were good then the back lite came back on. Well the next day i got in the car and started it and it is out again can anyone tell me what would cause this or did the display just go out because of age it is a 2000 model