Glad that it was just a cable thing.

As to unclogging, I've found that wiping the cartridge's jets with an alcohol-moistened cloth works well.

Refill kits work fine. Somewhat messy operation, though, and I don't care how careful you are. Replacement cartridges for that printer (remember, it's really a Canon bubblejet) are widely available at low cost, though, so I wouldn't bother.