I tried all the reset codes and so forth you might find on other otherwise useful forums, and i have successfully modded 5 of these to print on DVDs, but this "operator error" and five yellow flashing lights was a tough nut to crack. I was about to give up and toss it when I tried one more thing and it works!|
With the cartridges removed and the printhead carrier in the central position, press the empty printhead's back gently but firmly about a dozen times back against the printhead carrier, pushing it in toward the rear of the printer. I think this may help improve a bad contact between the half a dozen or so rows of little metal contacts on the printhead and their corresponding protruding little metal pins on the printhead carrier. It feels a little spongy (you can feel some give) as you push it in toward the rear of the printer and it gently springs back forward.
This solved it for me. I thought I'd share my idea and successful solution, and I hope it helps you, too.