I had the most difficult time last night trying to upgrade to OSX Snow Leopard. I performed the upgrade and was presented with a blank screen when my mac mini rebooted. I assumed that my resolution had been changed to some mode my television didn’t support so I tried all sorts of things to try and right the situation, but even booting into safe mode resulted in a black screen.
After hours of trying to work out a way to force the mac mini to use a more sane default resolution on boot I finally thought to pull out the hdmi switch I was using and connect the mini directly to the tv. And low and behold, I had video. My tv was obviously broadcasting that it was capable of 1080p, but either a bad switch or cable was reducing the hdmi bandwidth to the point that the resulotion was not actually possible.
So, the HDMI handshaking process seems pretty flawed to me, there should be some way the source can test different modes, and the destination should be able to report success or failure of different modes. A simple capabilities list simply isn’t cutting it. That and its pretty deplorable that apple often makes things WAY TO HARD by making them so simple. Why should SAFE MODE try to probe for capabilities of the destination device instead of picking a SAFE resolution to display in, and why should an OS upgrade try to pick a new resolution than the one I had manually selected? (1080p is a bit hard to read on my TV).
The other unexplained mystery is why my pc (and osx 10.5) could display 1080p content to the tv through this same switching hardware but snow leopard can’t? A bit boggling, to be honest.