My compass/temp display quit working. Any ideas?

[stephenfarris]

I have a 2003 GMC 2500hd. The compass/temp gauge just stoped working. It has been intermediate for the last few months. Sometimes it was dim, sometimes I could unplug it them plug it back up. I cleaned the ground wires under the front bumper and checked the sensor behind the grille. The green light on the mirror comes on and the auto darken still works. It doesn't matter if I unplug the connector behind the mirror or not there are still no numbers or compass. It doesn't even flash a blank green screen when I start the truck anymore. It acts like the power or fuse went out. I don't think that LCD screen give that many problems so I don't think that it is the mirror screen. Any ideas before I replace the mirror?