How do I troubleshoot a Canon G3020 printer with error 5100?

To troubleshoot, first check ink levels. Then, try cleaning the print head using the printer's built-in cleaning function. If that doesn't work, you may need to manually clean the print head using distilled water and a lint-free cloth, following Canon's specific instructions for this process. Finally, if cleaning doesn't resolve the issue, contact Canon support or a qualified technician.