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HP Designjet 700 Series Printers - Solving Media Skew and Jamming Issues

	Parts required (part numbers are subject to change)
	Cleaning the drive roller
	Checking or replacing the media spindle
	Checking or replacing the right roll-feed assembly
	Checking or replacing the overdrive gear assembly or overdrive assembly
	Accuracy calibration

KRS document number: BPP90039

Last updated: 22-Aug-2001

Minimum skill level: 2

Media skewing issues on the HP Designjet 7xx Series printers can be attributed to several causes. The most common causes of media skew are a dirty Drive Roller, malfunctioning Right Rollfeed assembly, or a faulty Overdrive Gear assembly. Other causes may include the media spindle, the media itself, or the Overdrive assembly. Use the steps below to determine the actual cause of the skewing issue and to replace the appropriate parts.

Parts required (part numbers are subject to change)

Part description	Models - C4705A/B, C3195A, C4708A/B	Models - C4706A/B, C3196A, C4709A/B, C3198A/B
Right Rollfeed Assembly (Required)	C4704-60199	C4704-60199
Media Spindle (Required)	C2847-60093	C2848-60011
Overdrive Gear Assembly (Required)	C4705-60089	C4705-60089
Overdrive Assembly (Required)	C4705-60121	C4706-60121

Cleaning the drive roller

If parts are replaced or fixed in any of the steps listed below, attempt to verify printer functionality by turning the printer on and printing internal test prints. If functionality is verified, no additional parts should be replaced.

1. Turn the printer on.
2. Press ENTER when printer completes initialization.

NOTE: Certain printer failures can occur that will prevent the printer from completing initialization. If this problem occurs, turn the printer off. Press and hold down the ENTER and UP arrow buttons while turning on the printer, this will allow access to the Service tests submenu.

3. Using the ARROW keys, scroll to Utilities, and press ENTER.
4. Using the ARROW keys, scroll to Service Tests 22 X Motion control, and press ENTER.
5. The Remove Media Press Enter message should appear. Remove any media from the printer.
6. Raise the printer's window (holding the window sensor down with a pen, pencil, or small screwdriver).
7. Press ENTER.
8. Press the UP arrow until the drive roller reaches a convenient speed for cleaning.
9. Using a lint-free cloth (dampened with water), thoroughly clean the entire drive roller surface while it is rotating.
10. Press ENTER to stop the roller.
11. Press ENTER to return to the Service Tests menu.
12. Press PREVIOUS until Status Ready for Media is displayed.
13. Allow the driver roller to dry.
14. Try loading media.
15. If loading is successful, repeat the loading procedure with roll and sheet media (preferably larger than 8.5 x 11 inches) two times each, to prove product functionality.
16. If loading is unsuccessful, or problems persist, continue with the remaining steps.

Checking or replacing the media spindle

1. Remove the media spindle from the printer.
2. Check the right side of the spindle for damaged or missing teeth. Replace the spindle if needed.
3. If the spindle is replaced, load media onto the new spindle, and try reloading media.
4. If loading is successful, repeat loading procedure with both roll, and sheet media (preferably larger than 8.5 x 11 inches) two times each, to prove product functionality.
5. If loading media is unsuccessful, or no problem is found with the media spindle, continue with the remaining steps.

Checking or replacing the right roll-feed assembly

1. Remove the media spindle from the printer.
2. Check the right rollfeed assembly for ease of rotation and for damaged or missing teeth. Use the eraser end of a pencil to move the Rollfeed assembly.

NOTE: The right rollfeed assembly gear should be very hard to rotate.

3. If the rollfeed assembly moves easily, it does not move at all, or it has damaged or missing teeth, replace the rollfeed assembly.
4. Following replacement, attempt to verify functionality.

NOTE: No calibrations are required if the right roll-feed assembly is replaced.

5. Verify printer functionality. Perform media loading procedure with roll and sheet (preferably larger than 8.5 x 11 inches) media, two times each.
6. If media loads correctly, the problem is solved.
7. If no problems with the rollfeed are found and the problem is not solved, continue with the remaining steps.

Checking or replacing the overdrive gear assembly or overdrive assembly

1. Open the printer's window.
2. Manually lift the bail assembly.
3. Try turning the overdrive wheels backwards by hand.
4. If the overdrive moves backwards, replace the overdrive gear assembly.
5. Following replacement, perform an accuracy calibration (listed below) and verify functionality.

NOTE: The overdrive assembly should only be replaced if noticeable damage is present. If the overdrive is replaced, perform an Accuracy calibration.

Accuracy calibration

1. Place a sheet of polyester film over the top of the printer for approximately ten minutes to let it stabilize to the environmental conditions. Use a sheet of approximately D-size (61 x 91 cm, 24 x 36 in). Roll media may also be used. When using polyester film, load it with the matte (dull) side down.

NOTE: If a polyester or matte film is not available, use HP Coated media when performing an Accuracy calibration.

2. Remove all media that is already loaded in the printer before performing the calibration.
3. Press ENTER at the Status display.
4. Use the arrow keys to scroll to the Utilities menu, and press ENTER.
5. Simultaneously press the ENTER and UP arrow keys to access the Service test submenu.
6. In the Service Tests submenu, scroll to 3C Accuracy Cal, and press ENTER.
7. The message, Create pattern/measure pattern appears.
8. Press the UP arrow to select Create pattern.
9. The message, Status/Calibrating, appears while the printer is calibrating.
10. When the printer is finished calibrating, the message Load media for calibration, appears.
11. Load the media. If using D-size media, load the short edge as the leading edge in D-size printers and the long edge as the leading edge in E-size printers.
12. When the media is loaded, the printer will automatically begin to plot the pattern.
13. A message Status/Printing, appears while printing.
14. Remove the media when the printer is finished printing.
15. The message Create Pattern/Measure Pattern appears.
16. Press the DOWN arrow to select Measure Pattern.
17. Rotate the plot so the edge with the arrows point toward the printer, and reload the plot with the arrow edge print-side down.
18. The printer will load the plot and measure the alignment marks using the line sensor on the carriage.
19. If the calibration passes, the message Success Calibration/Press Enter appears.
20. Press PREVIOUS until Ready is displayed on the printer's front panel.
21. Turn the printer off, then on and verify functionality.

Copyright (C) Hewlett-Packard Co. 2001
This information is subject to change without notice and
is provided "as is" with no warranty.
Hewlett-Packard shall not be liable for any direct,
indirect, special, incidental or consequential damages
in connection with the use of this material.

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