I have a HP G42. It was working but would randomly halt or restart the X session while running ubuntu 11.04.
Finally, last night, it froze and was not able to boot anymore. It gets stuck in the ubuntu splash screen, an if I choose the recovery mode in grub, it sort of halts in the session selection menu.
I have already run a memtest and it passes without errors.
How to proceed to further debug this issue?