Saturn S300 Series Service Manual page 131

Maintenance
Nozzle
Plate
Figure 6-21. Breakoff Point Initially Moves Toward Nozzle
Nozzle
Plate
Figure 6-22. Foldback Occurs When Breakoff Point Reverses Direction
b. Gradually increase the nozzle drive level. The position of
the breakoff point should be moving toward the nozzle
plate (away from the front end of the printhead) as you
increase the nozzle drive level. (Refer to Figure 6-21.)
Breakoff Point
c. Continue increasing the nozzle drive level until the
position of the breakoff point reverses direction and just
begins to move toward the front end of the printhead. The
nozzle drive level at which the stream reverses direction
is the foldback level.
Breakoff Point
Foldback occurs when the breakoff point reverses
direction and moves toward the front end of the
printhead as you continue to increase nozzle drive level
CAUTION: The breakoff point may disappear from view in the
charge electrode window while you increase the nozzle drive level.
If this occurs, observe the ink stream until the breakoff point
comes back into view. The final nozzle drive setting must be
below the foldback level.
4. Locate the print window, or the nozzle drive range that yields
good print quality, using the following procedure.
Gradually decrease the nozzle drive level below the foldback
level you located in step 3 to determine the continuous nozzle
drive range of values (or print window) that satisfies all of the
following conditions:
The print quality must be acceptable. (Perform several test
prints with the font you intend to print when the above
conditions are met to determine the print window, or the
range of nozzle drive values that yield good print quality.)
The breakoff point must lie inside the charge electrode.
6-28
Front end
of Printhead
Direction of
Ink Stream
Front end
of Printhead