Canon iPF840 User Manual page 576

When to Replace Ink Tanks
Before print jobs and maintenance that consume a lot of ink
If little ink is left, there may not be enough for large-format printing, head cleaning, and maintenance, which require
a lot of ink. In this case, replace or prepare to replace the Ink Tank before maintenance.
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 Dis-
play Screen, and printing is disabled. Replace the Ink Tank at this point.
576
Ink insufficient.
Replace ink tank.
OK
C M Y B
M
B
K
K
No ink left.
Replace ink tank.
OK
C M Y B
M
B
K
K
iPF840
User's Guide