I did a fresh installation of centos7 on a Lenovo T420s. But after rebooting the machine after the installation process finished I get messages of CPU got stuck for 22sec. This happens after logging in at gdm. I can't do anything - the machine hangs completely. Switching to tty only works before logging in at gdm. I really don't have an idea. My other T420 (without "s") works fine. Any help is appreciated. Thanks in advance Tim