'99 S80 T6 display

I have a 1999 S80 T6 w 150K miles. Over the past few days part of the LED
display started disappearing:

First the F (in degree units) went to a stick (like I), then within a day
or so the second digit went on the actual degree measurement so 70 F now
looks like 7 I. Now another day or two later the D for "Drive" lost its
bottom line. All of these are wihin a short distance of each other - the
rest of the display is fine. Another strange thing is that at night when the
lights on the dash dim, everything works perfectly!


Any ideas on what this could be? Also, I am not about to mess with removing
the dash, etc, so any idea how much something like this might cost at the
dealer? Finally, the bulb behind the temperature setting knob went a couple
of months ago - should it be any more "labor" to get to that if one already
has the thing open to repair the above? (I can definitely live without the
knob light.) Thanks.