There can be many reasons as to why your printer is not printing black. The most obvious cause can be the low ink, check and replace the ink cartridges. If still, Canon printer not printing black. It may be because of the clogged print head nozzles. Clean the nozzles. You can also fix it through the settings. Go to the windows and open printer driver setup. There would be a page setup tab. Click on the print options. From the drop down menu, click on color black only. 

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