I have a 3700 that just started having display problems. After it’s on for for a bit, the level meter, display lights and the am/fm display all go dark. I still am able to get sound from when I try all the inputs. If I turn it off and let it sit a few minutes, everything is turns on as it should. Then after a while again I lose all the lights and displays. Anyone ever seen this happen before? Hoping someone might know where I should look first.