My Canon i9900 seems to have a clogged color - cyan. I've cleaned and deep-cleaned and still no results. What can I do now?

A couple of things could be wrong.

Have you removed the cartridges and cleaned the nozzles with a damp, lint free cloth. This will remove a blockage at the nozzle tip.

Also, sometimes using a clean pencil eraser and very lightly cleaning the contact points on the cartridge and then blowing any residual erasure debris away will clear cartridge problems.

Lastly and most importantly, are you using a new Canon Cartridge and not a refilled cartridge? If you are using a refilled cartridge, get a new Canon cartridge and if the problem still occurs, call Canon tech support.

i9900 cartridges do NOT have any contacts