Roland Advanced Jet AJ-1000 Service Notes page 198

Rotate Adjustment Screw CCW (to the direction to loosen)
when Belt is in the lower position from the center of Drive
Pulley shown in the figure.
Tighten up Screw1 and 2 shown in the figure with pressing
6
Drive Shaft Support downward with 2kgf (0.2Nm).
tighen up Screw 3 shown in the figure until Screw 3 hits
Scan Motor Base
with 2kgf (0.2Nm).
After tightening up screws, check that Scan Motor Base and
Drive Shaft Support is parallel.
Move Head Carriage over a few times in a whole width and
check the position of the belt on Drive Pulley again.
NG
Adjustment
Screw
Screw 3
Then,
Screw 1
<Front View>
Scan Motor Base
4-51
Screw 2
Screw 3
Screw1, 2
Drive Shaft Support