I had a TT with the same issue since it was outside in the cold in my carport during the winter, I had no need to send the instrument in, just gently heat up the display once out, sure you need to take the cluster apart, then sweep over the crystal area cross pattern where you know the pixel issue is, with some low heat applied, resolved, 1000$ for such a fix, not even if the display is messed up, those are not that expensive to replace, and yes, always disconnect the battery and leave it idle for at least 15 minutes before you disconnect any instrument cluster connectors, common practice for legit workshops

This and BPR probably saved me $1000 dollars from the local mechanic.

do you not need to disconnect the battery doing this? these audi's are so sensitive