I have an Ubuntu laptop that stops responding when booting up. It will change between consoles with ctrl-alt-FN but pressing enter in the console would not even enter a blank line. The last printed line when booting up in recovery mode was "Skipping EDID probe due to cached edid". Any ideas what might be wrong?

Pressing ctrl-alt-del successfully rebooted it when in that mode. Another symptom is that GRUB stopped booting automatically, not sure if related (I doubt it).