Ricoh M126 Service Manual page 198

6. Press or to the desired setting, and press.
7. Print the Quick Test page again and check that the darkest line in the center graph is equal to
zero. If it is equal to zero, then check to see if the left, top, and bottom margins are visible. If it
is not equal to zero, then repeat step 5.

The alignment of the left margin positions the black plane to the right or left. The
alignment of the right margin does not alter the margins and should only be used to
adjust the printhead.
SM
Printhead Assembly Electronic Adjustment
5-49 M126/M127/M128