Brother DCP6690CW Service Manual page 309

(4) Move the head/carriage unit to the center of its travel with function code 63 (see
Section 9.4.17) using the following key operation.
Models with numerical keypad on the control panel: Press the 6, 3, and Black Start (Mono
Start) keys in this order to display "START 63?" on the LCD. Next, press the * key.
Models without numerical keypad on the control panel: Press the 6, 3, and Black Start
(Mono Start) keys on the software keypad in this order to display "START 63?". Next,
press the Scan and Copy keys simultaneously to switch the software keypad between the
numerical and function keypads, then press the * key.
(5) Turn the head skew adjuster knob by the number of divisions specified by the pattern
number you recorded in step (3), using a spanner.
If block +1 is the least uneven print, for example, turn the head skew adjuster knob
clockwise by one division; if block -1, turn it counterclockwise by one division.
Counterclockwise
(6) After completion of the adjustment, press the Stop/Exit key. The head/carriage unit returns
to the home position (head capping position).
Clockwise
Head skew adjuster knob
(head_skew_adjuster_knob_BHM9)
7-15
Chapter 9,
Confidential