Canon BJC - Recent Questions, Troubleshooting & Support - Page 4

You might need to clean the whole print head as well. Open the printer, remove the cartridges and press the lever to release the whole printhead. Place the printhead (while it is standing upright) in a small dish with a few mm of lukewarm water. The dried-out ink will dissolve (you can see this because the water will take color). Repeat if necessary; it may take a whole night before all the dried ink is dissolved. You might then even have the luck that your old cartridges will work again.