Digital Equipment DEClaser 320, Руководство по обслуживанию

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7.6 Deletions, Blank, or White Spots
7.6.3 Random or Localized White Spots
Description: Random or clusters of white spots or large blotchy
white areas.
Troubleshooting: Perform the classification procedure, as shown in
Section 7.6. Perform the following procedure:
1. The paper might be damp. Try some dry paper from the center
of a fresh package.
2. If the spots occur at intervals of approximately 4.92 in (125 mm)
the photoreceptor may be damaged.
3. Inspect the heat and pressure rollers for contamination or
damage. Swap the fusing unit.
7.7 Extraneous Marks
Description: Horizontal or vertical bands or other marks.
Troubleshooting: Print copies of the grid test pattern, as shown
in Section 3.3 and the 1948 Setup pattern, as shown in Section 3.3.
Also, ask the customer to print samples of the offending defect.
Analyze the printed samples and go to one of the following:
1. If the defect appears on the grid pattern, inspect the print drum
ground clips. When the top door is closed, this clip connects the
metal print drum axle to the frame of the printer.
Use an ohmmeter to measure the resistance between the metal
part of the print drum and the frame of the printer. If the
resistance is greater then 10
, replace the ground clip.
2. If the defect appears on the 1948 Setup pattern, swap the video
control board.
3. If the defect appears on the customer samples, do the following:
a. Ask the customer if the system has been recently
reconfigured.
b. Try different fonts. The downline loaded font data from the
host might be bad.
7–10 Image Defects FIPs