Ubuntu不能正常开关机

首先，不能正常关机：

Q: Ubuntu点击关机后停留在splash界面不动

A: 解决方法来自Shutdown does not power off computer

I have the same problem and found a solution which worked out for me.

Type in terminal:

1. 1.  sudo -i  (to get a root shell, sudo gedit is not recommended)
   2.  gedit /etc/default/grub 
   3. Find the line:  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" 
   4. Change this to:  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=force" 
   5. Save the file and close the file.
   6. Finally, in terminal:  update-grub 
   7.  exit  (to end the root shell)

I found it here: Dell Studio 1569 Cannot Shutdown in Ubuntu 11.10 or 12.04

其次，不能正常开机：

Q: 开机后，屏幕提示 “PXE-E61: Media Test Failure, Check Cable” ，然后就是跳转到找不到操作系统。只能通过手动选择Ubuntu这个启动项才能启动操作系统

A: Waiting...

可参考：http://www.tech-faq.com/how-to-solve-pxe-e61-media-test-failure-check-cable-error.html