Repairing a Canon Pixma G3510

Reported problem: doesn't print anymore.

• Black ink light flashing - manual doesn't specify what this means, but will assume out of ink.
• Colour ink light solid - suggests low ink.
• Detects paper and paper size fine.
• Try printing a test page.
• Paper pickup doesn't seem to be working - starts pulling it in, but then stops, and gives error about no paper.
• Paper pickup cleaning maintenance mode doesn't work.