Tektronix Phaser 840, Service Manual

Page: 195 / 207

184 Phaser 840 and 850 Color Printers
11: Head-to-Drum Gap . This print
indicates if the gap between the printhead
and the drum is correct.
Lines . The horizontal lines of the print are
made up of long lines and short dashes. If
the dashes are positioned above the lines,
then the drum gap is too wide.
If the dashes are positioned below the
lines, then the drum gap is too narrow.
Also examine each end of the band of
text. Look for differences between the
quality of the characters on the left and
right ends of the print. A difference
indicates that the printhead is misaligned.
Text . Look for text that is fuzzy or text that
differs in quality from one side of the print
to the other. Either condition indicates
that the printhead-to-drum gap is
incorrect.
Perform the procedure “Printhead-to-drum
spacing adjustment (Phaser 840 printer)”
on page 102. Generally the Phaser 850
printer. should never require this
adjustment
12.: Manuf. x-axis (scanner) . This print
is used for manufacturing and engineering
evaluation of printhead performance.
0388-39
Time_to_Drum/Head_to_Drum test print:
Short dashes above the line indicate large time_to_drum and/or large head_to_drum gap.
Short dashes below the line indicate small time_to_drum and/or small head_to_drum gap.
EFGHIJKLMNOPQ
EFGHIJKLMNOP
FGHIJKLMNOPQ
EFGHIJKLMNOPQ
EFGHIJKLMNOP
EFGHIJKLMNOP
Indicates
that head-to-drum
gap is too small