When the 30-inch Cinema Displays were first released, some users reported pixel distortion, i.e. the screen seemed to sparkle or have patches of "dancing" pixels. In addition, some displays had dark bands or half the screen was dimmer than the rest. This turned out to be usually caused by the backlights warming up.
Currently, there are a couple of issues with these displays that have developed over time. One of these is the screen getting stuck at full brightness, with none of the controls apparently being able to change the brightness levels.
