Canon imagePROGRAF iPF765 MFP M40 - Manual (Page 626)

If a message for ink replacement is shown on the Display Screen
When ink runs out, the Message Lamp flashes, a message regarding Ink Tank replacement is shown on the Display
Screen, and printing is disabled. Replace the Ink Tank at this point.
When to Replace Ink Tanks iPF765
User's Guide
Maintenance and Consumables
Ink Tanks
626