I'm running ubuntu 14.04 on a Acer E17 laptop. From one to another the computer seems to freeze during the boot sequence. It boots to grub without an issue, but when I select Ubuntu it seems to freeze on a black screen. No indication as to what it's doing or any error code. Normally it would display the word Ubuntu with 5 dots beneath it that change from white to red.
If I boot the recovery boot (of the same kernel) and in recovery immediately hit resume it boots normally and I can login.
I already tried to downgrade some recent updates using synaptic, but that did not help. The next thing I tried is to try to create some boot logs with bootlogd, but
/var/log/boot.log remains empty. Does anyone have an idea where to go next?
Edit: after a couple of days
/var/log/boot have some information, but no errors of any kind.
cat /var/log/boot produces this output: http://pastebin.com/FEjBveEG
cat /var/log/boot.log produces this output: http://pastebin.com/iycLg0p0
(formatting is off, no idea why, it isn't in the output)