I found a million threads about the cluster display fading (my Missy is a sad victim of the same fate), but I haven't been able to find any about the HVAC pixels going wonky.

This is very similar to what happens in a lot of late 90's/early Ought's Bimmers on their LED lettering, but in opposite - the individual pixels are going full bright where they shouldn't. See the pictures below (my car isn't nearly as dirty as the pics suggest ). This stemmed from shutting off my fan completely while smoking a cigarette in my car at work during the pouring rain, in case that matters at all... when I turned off the car and turned it back on, the fan was at full blast for some reason, and then this mysteriously started happening.

http://www.flickr.com/photos/6075575...in/photostream

http://www.flickr.com/photos/6075575...in/photostream

http://www.flickr.com/photos/6075575...in/photostream

Anyway, as you can see, it's slowly spreading and moving. Any idea how to slow or stop the progress before I have to start adjusting my heat by feel?

 

Bump, any ideas?

 

never saw this before strange

 

Yeah, never seen that before.

Maybe if you removed and shook it a while, it will all erase, like an Etch-A-Sketch.

My guess is that you'll need an entire new unit eventually.

 

did you hit the screen by accident?

 

yes, it is "broken" and the "liquid" in the Liquid Crystal Display is "leaking"....could be from HEAT or IMPACT.

Look up M3 rear view mirrors...pretty common!

 

Nope, no impacts or excessive heat. Oh well, I can probably find a spare or reman that won't cost too much. Maybe try to wire up a C55 one

 

well a c55 one would work just fine same plugs but the fit would be an issue.

 

Eh, I'll just take a Dremel and some bondo to the edges

 

This is a common problem on the main display between the clocks on post 2005 facelift vehicles. Biggest culprit the SLK. Only fix is replacement.

 

Oh, the later units do it too?

 

Yes - it's slightly less noticeable on later units until they get really bad because they use higher definition displays with much smaller pixels. It's not that common but it happens. While searching recently for a new ultra low mileage car I found a number of cars with the problem.