How to Troubleshoot Canon Printers

See if your Canon printer has its indicator lights flashing in a specific pattern and then consult your manual to see if there is a corresponding error code. Follow the instructions in the manual for how to fix the associated problem, or continue on with more troubleshooting if it isn't displaying a specific error code.
Make sure the power cord is plugged into your wall outlet and the USB cable is firmly connected to your computer. Open the top of the printer and do a quick visual inspection to see if there is a piece of paper stuck in the paper feed.
Restart your computer and attempt to print off something new in case the computer has stopped recognizing your printer or the print queue has stopped responding due to a software error.
Navigate to your computer's 'Control Panel' and click on the 'Printers and Faxes' option. Click on the 'Add A Printer' button if your Canon printer isn't showing up in the list. Follow the on-screen instructions so that your computer will run a test to try to detect the printer.
Try uninstalling and re-installing the Canon software that came with your printer and then navigate your Web browser to their official Web page and download the most recent version of the software driver.
Open the Canon printer software and choose the 'Properties' or 'Options' tab. Click on the option to 'Test Alignment' or 'Clean Print Heads,' depending on which version of the software you are using. Wait for the printer to finish its alignment and then print off a test page. Check to see if the test page printed properly and then contact Canon for repair or replacement options if it still isn't working properly.