Typical problems with printers and scanners

• "The system printing service doesn't seem to be available" message.
  
  
  
  If you see this message make sure that you have cups installed and that it is properly running..
• "No scanners detected".
  Sometimes you can have some problems to detect scanners from software such as xsane. If so, try to execute xsane as sudo. If you can detect your scanner as super user, the it is probably that you have no permissions as a simple user. To fix it, use lsusb to determine the device of your scanner, navigate to /dev/bus/usb/$BUS/$DEVICE and check the permissions of that device, i.e. what group it belongs to. Try to give your user the necessary groups for it, or if that fails, chmod the device (as suggested in the thread). (from: http://superuser.com/questions/104184/xsane-is-unable-to-detect-scanner-device).
•  Related commands: lsusb, sane-find-scanner, scanimage -L