Before you undertake the Canon printer troubleshooting, you must understand that you are looking for a specific scenario to resolve. These are the possible causes of problems, such as Canon printer not printing, Ink cartridge not responding, or Canon printer offline. In such cases, keep a watch out for loosened USB connections. Another issue might be a connectivity problem or a cartridge problem. There is a chance that your Canon printer's ink has got depleted. Hence, you can either replace the cartridge or fill the ink tank of the Canon printer.