I upgraded from Debian Wheezy to Debian Jessie by changing sources from
/etc/apt/source.list and running:
apt-get update apt-get --download-only dist-upgrade apt-get dist-upgrade
This operation went fine and didn't seemingly break anything. However after shutting down computer and starting it again the login screen is not appearing after Grub menu. The screen is black after grub and it doesn't seem to respond to any key combinations. I have tried choosing recovery mode from Grub, but it doesn't help with the problem. Any ideas how I should start investigating this problem? I'm fairly new to Debian and I'm not sure how to fix this problem. Is there some way I could open the terminal and find logs about booting?
Edit: Pressing CTRL + ALT + F2 does not open shell. No key combination works in the black screen. My graphic card is AMD Radeon HD 7970.