Helpful hints with regard to Canon print heads

by Andy Ng on August 20, 2021 Categories: Tech Tips

Canon print heads use a heat process to eject ink from the print head. Imagine a line of very small tubes filled with ink and little heaters near the tip of each tube. When the tiny heater momentarily heats up, a small air bubble forms in the tube. This, in turn, forces a small drop of ink out of the tip. This is where the term “bubble jet” originates.


Print head failures are often really heater failures. Much like the filament in a light bulb, they simply burn out. Since this is part of a circuit that can be tested, most printers will then flash lights or display an error on your computer related to the print head.
Sometimes the error may be a bit misleading; such a referring to head temperature, an incorrectly installed cartridge, a “wrong cartridge”, or missing cartridge. If the error is pointing even vaguely to the print head, that’s the best place to start looking for a solution assuming you’re not simply out of ink.


Naturally most print quality shortcomings are related to the print head. Many, however, are not entirely the fault of the print head. If you don’t print fairly regularly with your inks for an extended period, the nozzles in the head will begin to clog or build up residue that deflects the spray. Both issues result in “banding”. Banding generally shows up as faint lines through the image; either blank lines or discoloured lines. As residue continues to build up an entire colour may drop out causing discoloration of the entire image. This may be due to clogging nozzles but it may also indicate that the pump charged with cleaning the print head is clogged and no longer doing its job.


When you have a print quality issue the first step in troubleshooting the issue is to do what’s called a “nozzle check” test. In the Windows/PC world you can do this by clicking on Start, then Control Panel, then Printers. This should bring up a window that shows the printers installed on your computer. Right click on the name of the printer in question then select Properties. This opens the printer driver – the software that was installed from the CD that came with the printer. The nozzle check test should be under a tab named something like “maintenance” or “utility”. The nozzle check test prints a sample of each ink colour in a grid or block pattern. Problems with print quality are usually obvious on the nozzle check sample.

If you find missing lines, run a cleaning cycle and reprint the nozzle check pattern. Sometimes the colour will come back with a clean or a fresh cartridge.


If you print a nozzle check pattern and ink is missing in a very regular pattern such as half a block is missing or every other column in a grid is missing you may be in a bad situation. Missing part of a colour in a very regular pattern indicates that a portion of the head has electronically failed. Or that part of the signal to fire nozzles is not reaching the head. Unfortunately, there’s no way to be certain what exactly has failed in this situation.

At this point, replacing a print head is risky. We find it sometimes fixes the problem but just as often points to a problem elsewhere. If the latter is true, you’ve likely written off the print head that was just installed.