HP LaserJet 5000 Service Manual - Page 171

Top Margin Adjustment When the terminal PCA is replaced in the field, the top margin needs to be re-adjusted. Also, if the top margin of test prints made after laser/scanner unit replacement is not 2.0 mm, this adjustment is necessary. The adjustment procedures are shown below. 1 After setting the VR401 on the terminal PCA to the center position (+/-0), set A4-sized paper in the tray. Press the test print switch to make several test prints. 2 Measure the length from the leading edge to the print pattern ("a" in Figure 6-24). Measure all the test prints and calculate the average. 3 Adjust VR401 so that the calculated value in step 2 becomes 2.0 mm. The pattern image shifts in the "+" direction in Figure 6-25 if VR401 is turned clockwise, and in the "-" direction, counterclockwise. Turning the VR401 one scale shifts the pattern about 0.8 mm. For instance, if the average value calculated in step 2 is 2.8 mm, the difference is 0.8 mm. Therefore, turn VR401 clockwise for one scale. (See Figure 6-25.) 4 Make several test prints again, and perform step 2. Check that the top margin is 2.0 mm. If the value is incorrect, repeat steps 1 through 4. Figure 6-24 Adjusting the Top Margin 6-32 Removing and Replacing Parts EN