Every once in a while, my Apple 30" Cinema Display freaks out and it takes me an hour or so to fix it. I've got it attached to a 15" Powerbook with 128 Mb of VRAM, so the set up is OK, and it mostly works, so there's nothing structurally wrong as far as I can tell. The problem exhibits itself in one of two ways:
- The display is only recognized as having a maximum resolution of 1280x800 (see see picture)
- The display creates two 1280x800 bands top and bottom that are duplicates of each other. (see picture)
Putting the Powerbook to sleep, rebooting, hot plugging and unplugging, shutting down, restarting, and various combinations of these only serve to toggle between these two modes most of the time. Selecting "detect display" from the Monitor preferences pane has no effect at all. If I play around with it enough eventually I can get it to work and then it will work for weeks. This behavior happens on both OS X 10.3 and 10.4. My 23" Cinema Display at home works flawlessly.
I'm convinced that there's something wrong with either the Powerbook or the display since there's nothing on Google or Apple's support forums that I can find on it. If I'm the only one having the problem, then its likely a hardware problem. The trouble is how to diagnose and fix the problem. I've not been able to find any consistent way to fix it or any clues that tell me why its happening.
I've called Apple support and they want to walk through all kinds of scenarios like "do you have another Powerbook/Display you can try" etc. Without some kind of concrete diagnosis, they're answer is to take it to an Apple Care center.
I hate the thought of that because (a) I've got to lug that huge monitor there and (b) the problem only turns up every once in a while. I'm not sure they'll be able to diagnose it.
Any ideas anyone?