Whenever I boot ubuntu 12.04 from grub, it takes me to the login screen but the screen is completely blank (no backlight at all). I'm running a 64-bit Compaq Presario CQ45 with Intel Intergrated Graphics (Intel(R) HD).
I can connect the laptop to an external display at see ubuntu fine on the external display, but I can't see ubuntu on my laptop screen unless I change the resolution down a little and then ubuntu appears on my laptop. But this only lasts for about 30 minutes and the screen goes blank again.