· Prints "stair steps" down the left margin of the self-test page.

· The left or right margins of the self-test are not properly placed.

· The ink cartridge carriage slams to the left side of the HP DeskJet or DeskWriter printer.

· The self-test shows double-printed or shadowed letters.

· Flaws run down the length of a printed page (portrait orientation), or across the page (landscape orientation).

· Printing stops, and the control panel lights on the HP DeskJet or DeskWriter printer indicate an error.

· Gaps appear in printed text or images.

· Slow printing

CAUTION: Do not clean the encoder strip for the following symptoms: media pick issues, paper jams, paper skewing, ink-cartridge rejection, missing dots or white streaks through print, and smeared or streaked black ink.

SOLUTION: Clean the encoder strip inside the HP DeskJet or DeskWriter printer by following the steps below:

NOTE: Extreme care must be taken during the cleaning process. If too much pressure is placed on the encoder strip, it could become scratched (destroying the etching on the strip), bent, broken, or even become dislodged from the inside of the HP DeskJet or DeskWriter printer. If damage of this type occurs, the HP DeskJet or DeskWriter printer must be returned to HP for repair.

1. With the HP DeskJet or DeskWriter printer on, open the top cover to allow the print cartridge cradle to move to the center of the printer. (For the HP DeskJet 510, 520, 550C, and 560C printers, open the top cover, and then press the Install Print Cartridge button on the printer's control panel.)

2. Unplug the power cord from the HP DeskJet or DeskWriter printer.

3. Slide the cradle to the far-right position.

4. Identify the semi-clear mylar encoder strip, located just behind the round, metal, cradle rod.

CAUTION: When pulling the cloth along the encoder strip in Step 5, grasp the strip gently, to ensure that the strip does not break. Pull the cloth in a right-to-left direction.

5. Moisten a clean cloth or tissue with water, then gently grasp the strip between the thumb and forefinger, and carefully pull the moistened cloth along the entire length of the strip in a right-to-left direction. Repeat this step with a different portion of the cloth to ensure that all foreign matter is removed.

6. Move the cradle to the far-left position and repeat Step 5 on the right side of the encoder strip, beginning as far right as possible. Again, gently pull the cloth in a right-to-left direction.

7. Allow the encoder strip to dry, or gently dry the encoder strip with a clean, dry cloth or tissue.

8. Position the cradle near the center, and then plug the power cord into the HP DeskJet or DeskWriter printer.

9. Close the top cover to allow the print cartridge cradle to move back to the right of the HP DeskJet or DeskWriter printer. (For the HP DeskJet 510, 520, 550C, and 560C printers, press the Install Print Cartridge button on the printer's control panel, and then close the top cover.)

10. Print a self-test to ensure that the HP DeskJet or DeskWriter printer is functioning properly.