This is how to reset Canon iP 1880 :
1. Press Resume button and hold for 1 - 2 minutes
2. Open the cover
3. Release the catridge and then put them on again
4. Close The Cover
5. Turn off the printer
6. Turn it on again.
Or you can use IPTool software to reset,
Step 1 : Manual for service mode
1. Unplug power and USB.
2. Open door and hold power button.
3. Connect power.
4. Close door, then release power button.
5. Open Iptool then klik "Reset Main"