The lamps are for back lighting the LCD at night. If the numbers aren't showing, then it's time for another LCD screen so the numbers work.I still you just have lamps burning out on you. I would pull your dash out enough to get at the lamps and pull them out and look at them. There is differant lamps bepending on the area. The hardest ones to get at are the LCD display area and you have to take it complete apart to get at 1 or 2 bulbs. I just did my dash this winter with led bulbs. I had the same issue that it seemed dark in areas and that is what I found out, Dead lamps.
Good luck reddun1995!