Z61m screen not working after freeze/reboot

[Zak]

I've been having what I believe are driver-related freezes when I plug in/unplug my Z61m. It's running Linux with the latest fglrx driver. The freezes are intermittent, but only occur when switching the GPU's powerstate. I can cause them by switching the powerstate with aticonfig as well. When it freezes, a mostly random black and white image is displayed on the screen.

After a recent freeze, the LCD did not come on on reboot. The machine works fine with an external screen. According to the operating system, no LCD is attached. I also tried Windows 7, and it doesn't see the LCD either. I disassembled the machine and checked both sides of the video cable; I found no signs of a bad connection. I suspect the problem is the GPU itself, as I've had problems with it before. I'm wondering if anyone can suggest less extreme things to try before I decide to blame the GPU and take drastic actions.

[Zak]

It has mysteriously started working again after a reboot. Several attempts to get it working previously be rebooting and changing BIOS settings had no effect.