I am using 12.04. In addition to Canon MX870 printer only shows "Processing" on the status LCD, I'm not sure if I successfully removed the old MX870 driver (I removed it by using Ubuntu Software Center), then I added a new PPA, apt-get update and then: $ sudo add-apt-repository ppa:michael-gruz/canon-trunk $ sudo apt-get update $ sudo apt-get install cnijfilter-mx870series Reading package lists... Done Building dependency tree Reading state information... Done Package cnijfilter-mx870series is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'cnijfilter-mx870series' has no installation candidate How could I resolve this?