I was in a similar situation once i tried to reset the ink absorber and it worked for me. To get rid of this problem, you can also reset by turning off your device then press and holding the Resume button. At the same time, press and hold the Power button until the light starts to blink. After that, release the Resume button, press it two times, and then release the Power button. Furthermore, press the Resume button for times and then press the Power button right away. Check if the ink observer full problem still persists.