Hi CweeTeo,
Please follow these steps to try to resolve this issue:
1. Confirm that the printer is powered on.
2. Pull open the paper output tray.
3. Lift the scanning unit (printer cover) completely. The print head will move to the replacement position.
4. Open the inner cover.
5. Remove the ink tanks by pressing the tab of each tank.
6. Raise the print head lock lever.
7. Tilt the print head slightly towards the front of the machine and lift out gently.
8. Place the print head in the print head holder and lower the print head lock lever carefully until you hear a click.
9. Insert ink tanks into the print head.
10. Press the mark <PUSH> on the ink tank firmly until you hear a click.
11. Ensure that all the ink tanks are installed properly and the ink tank lamps light red.
12. Close the inner cover and the scanning unit/printer cover.
If you continue to have difficulties, please contact our support group using the following link:
http://Canon.us/ContactLI
