Cause
If the lamp on the ink tank flashes and you are receiving Support Code 1689, it means the printer is out of ink. This could be because:
Action
Replace the ink tank and close the operation panel.
If you want to finish your print job while in the ink out condition, release the function for detecting the remaining ink level. Then press and hold the Stop button for at least 5 seconds and release it. The ink tank displays in gray on the printer screen when the detect function is disabled.
If you halt the ink level function, the printer will stop monitoring the ink level for the applicable ink tank(s). Please be advised that Canon shall not be liable for any malfunction or trouble which may be caused by the continuation of printing under the ink out condition.