Free tv repair advice

Hello,
I Have An 50" 1997 Gig BOX TV ""Hitachi ""Its An Great Tv Until Now Its Model is 50X Fx30B The Picture is good but it shuts off after an couple of minutes and i can hear like its trying to connect but its not the red lite on off switch is off after about 15 minutes i try it works but than its shuts down again if it repairable is it worth it