Roland VersaCamm VS-640 Service Notes page 252

Confi rm the belt position.
4
The position is proper when the belt is not touching the
Flanges of the Drive Pulley excessively. When the position
is proper, skip this adjustment and go to [ADJUSTMENT ON
THE IDLE PULLEY SIDE] described in the later step of this
adjustment leaving the belt aging on. When the position is
improper, make adjustment as follows.
Belt partly touching the Flange is acceptable.
Press [ENTER] key to cancel Aging.
5
Release the Head Carriage and move it to the left by hands.
6
Remove the Right Under Cover and Right Side Frame.
7
SCAN
NOW AGING
Right Under Cover
4-54
Flange
[ ]
Right Side Frame