Adjustments; Parallelism Adjustment - Epson Stylus COLOR 440 Service Manual

EPSON Stylus COLOR 440, 640, and 740

5.2 Adjustments

The sections below provide specific instructions for each type of
adjustment.

5.2.1 Parallelism Adjustment

You must perform the parallelism adjustment after replacing or
removing the carriage guide shaft, or if you change the setting of the
parallelism adjustment bushings. This adjustment sets the standard
distance from the printhead to the paper surface.

Do not scratch the ribbed surface of the platen or the
C A U T I O N
special coating on the PF roller.

To avoid damaging the printhead, never use a rusty,
dirty, or bent thickness gauge. Clean the gauge
before using it, and avoid pressing it hard against the
head.
1. Set the right and left parallelism adjustment bushings to the center
position mark. This is where the ridge on the top of each bushing
aligns with the notch and the screw hole on the metal frame. See
Figure 5-2.
Right Parallelism Adjustment
2. Set the PG lever to 0 (forward). This minimizes the gap between
the printhead and the platen.
3. Move the carriage to the center of the platen. Then set the
thickness gauge on the right side of the platen as shown in
5-1 on the next page.
4. Move the carriage so it's over the thickness gauge.

Put the thickness gauge on the flat part of the
C A U T I O N
platen ribs, as shown in

Move the carriage by pulling it with the timing
belt.
5. Move the right parallelism adjustment bushing to the rear, which
narrows the gap, until the thickness gauge moves with the carriage
when you slide the carriage about 1 inch (20 mm) in either direction.
6. Move the adjustment bushing one notch forward to widen the gap.
7. Set the PG lever to 0 (small gap) and slide the carriage right and left
to make sure that the thickness gauge doesn't move with the
carriage.
Left Parallelism Adjustment
8. Perform steps 2 through 7 to adjust the left parallelism adjustment
bushing. But this time set the thickness gauge on the left side of the
platen (see Figure
Checking parallelism
9. Perform steps 2 through 4 again, with the thickness gauge set on
the right side of the platen.
10. Make sure that the thickness gauge does not move along with the
carriage when the carriage is moved about 1 inch (20 mm) in either
direction.
11. Move the right parallelism adjustment bushing one notch to the rear
Figure
(the gap will be narrowed). Then check that the thickness gauge
moves along with the carriage. If the thickness gauge does not
move, go back to step 2 and repeat the adjustment.
Chapter 5 Adjustments
Figure 5-1.
5-1).
118