Tektronix Phaser 840, Service Manual

Page: 155 / 207

144 Phaser 840 and 850 Color Printers
Installation. If not already in place, install the printhead’s data ribbon cable to
the printhead.
1.
Using the printhead removal tool, reverse the removal steps to reinstall
the printhead.
2. Rotate the printhead to its print position and attach the head tilt spring.
3.
Torque the mounting screws to 20 in/lbs.
Caution Be careful not to spill ink out of the hot printhead.
Adjustment Steps 4 through 8 are for the Phaser 840 printer only. Do
not loosen the printhead locking screws on the Phaser 850 printer.
The Phaser 850 has no printhead-to-drum adjustments.
4. Install the digital gap indicator and bracket to the left side of the printer
frame and tilt arm as described in the procedure “Printhead-to-drum
spacing adjustment (Phaser 840 printer)” on page 102. Ensure the
digital indicator is set to inches, “in.” Press Origin to zero the digital
indicator.
5.
At the left of the printhead, insert the left printhead spacer between the
printhead and the drum. Check the indicator, it should read 0.0030
+
/
-
0.0010 inches. If needed, lighten the four locking screws and then
adjust the printhead’s spacing adjustment by twisting a flat-blade
screwdriver in the adjustment slot to move the printhead’s position
until the indicator reads the correct value. This sets the “cold”
printhead-to-drum gap. Refer to the illustration, “Spacing the
printhead to the drum,” on page 104.
6.
Remove the left printhead spacer and install the right spacer between
the printhead and the drum. Repeat the adjustment.
7.
Tighten the four locking screws in an X-pattern.
8.
Remove the head-to-media gap indicator tool and bracket.
9.
Plug the printhead’s data ribbon cable and power wiring harness into
the power control board. Inspect both ends of the data ribbon cable to
ensure they are properly seated. Reconnect the two printhead ground
wires to the printer frame.
10. Install the ink loader.
11. Turn on the printer.
12. Phaser 840 printer: Refer to the topic “Printhead-to-drum spacing
adjustment (Phaser 840 printer)” on page 102 to set the correct gap
between the “hot” printhead and the drum.