Canon MP980 series On-Screen Manual page 717

Manual Print Head Alignment
Do not open the Scanning Unit (Cover) while printing is in progress.
12.
Check the printed patterns, and use the
pattern in column H that has the least noticeable vertical streaks.
Note
If it is difficult to pick the best pattern, pick the setting that produces the least noticeable vertical
white streaks.
(E) Less noticeable vertical white streaks
(F) More noticeable vertical white streaks
13.
Repeat the same procedure until you finish inputting the pattern number for columns
I to Q, then press the
14.
Confirm the displayed message and press the OK button.
The third pattern is printed.
Important
Do not open the Scanning Unit (Cover) while printing is in progress.
15.
Check the printed patterns, and use the
pattern in column a that has the least noticeable horizontal streaks.
or
button.
OK
or
button to input the number of the
button to input the number of the
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