Also ensure that all cables are in a loose state. In the event that they are loose, your computer isn't recognized by the printer, and consequently, you'll not be in a position to print anything.
Instructions for PC
Select the Start menu, then click upon"Printers" and click the "Printers and Faxes" icon.
Double-click the icon of the you wish to switch to online. A pop-up will pop up in which all current print jobs being queued on the printer's behalf are listed.
Select the printer tab on the menu that pops up. Make sure you have remove the checkmark "Use printer without a connection." This will change the printer's status from offline mode to an online.
Instructions for Mac
click on the icon in the Dock., click on the icon in the Dock.
Visit the control for printing and fax panel under the Hardware category.
Choose the printer you wish to choose from the list on the left of the display. Click on"Open Queue" button "Open queue" button.
Simply click on "Resume from printer" present at the top of the queue to switch your Canon printer from offline to on-line.
Alternate ways to change Canon printers offline to online
Update driver for printers: Drivers are software that maintain the functions of your printer, which includes connectivity. If you experience offline issues frequent, then make sure to test your drivers. Update them with the most current version currently available.
Increase the time of sleep: In the configuration panel of your printer, look for the idle mode to see whether the duration set is not sufficient. If it is, then increase the time to ensure that your printer doesn't often go into sleep mode.