Sounds like the capicitor in the display unit is failing. It is getting enough of a charge to display when you adjust the volume, but not enough to keep it on when nothing is being used. At this point is up to you if you want to send it in to be repaired. Does the display light up when switching inputs? I would ask myself how often do you look at the display and if you can makes adjustements using the GUI features then if it's worth sending it in for repair.