Ipod Screen in Dim

My ipod's screen is dark even when the battery is fully charged. I can hardly read the screen which makes it pretty hard to use when working out which is when I use it the most. I have checked the settings on the Ipod many times and I have the Brightness turned up as far as it can go. Changing the brightness has no effect on the screen. I have also tried to restore all the factory settings with no avail. The screen is too dark. The Ipod seems to function correctly otherwise. I do think this may be a problem with the battery because I have noticed that the battery doesn't hold a charge as well as it used to. I figured the unit was just getting old. Can this be fixed and is it worth it or should I just junk it?