I agree w/ blackmercedes. The same thing happened to me yesterday! I had the cluster out w/ the whole dash. I put it all back together and the left side of the cluster didn't work. The fuses looked fine but when I went to take out fuse #9 it was burnt. Try replacing it. It's a white 8Amp on my '91 190e 2.6.
Hope it's just a fuse!