My printer green and orange lights are blinking alternately

My printer green and orange lights are blinking alternately

I have a Canon Pixma IP4700. When I turn the printer on, both the green and orange light flash alternately. The ink cartridge’s are full. I have unplugged the printer and reconnected then restarted it, but the same thing happens. The error message comes up advising to take the steps I had already taken. How can I fix this?