HP Designjet T3500 Production eMFP - Manual (Page 234)

Actions
1. Open the scanner lid. Clean the motor wheels (small black rubber) and the pressure rolls (wide white
plastic). Check that all the pressure rolls can move freely. If you find dust particles or objects that
obstruct the movement of the rollers, try to remove them, then close the scanner lid and repeat your
scan.
2. If the problem persists, clean and calibrate the scanner as indicated in Scanner maintenance
on page 162 , and analyze pattern 1 of the diagnostic plot. If you can find horizontal periodical banding
inside this pattern, as shown on the right below, call HP support and report “horizontal periodical
banding”. Please note the black arrow indicating the scanning direction in this example.
Original Pattern 1 affected by horizontal periodical banding
Defocus, blurring and fading colors
CIS technology scanners are tuned to work at a fixed focal distance, and they are very sensitive to small
variations in the position of the original with respect to the scanner glass plate. If the scanner lid is not
properly closed, or if the original has deep wrinkles or texture, you may sometimes find problems as in the
following example (on the right), where the scanned image is blurred and colors are faded.
Actions
1. Check the scanner lid sensor by opening the scanner lid and checking that the five CIS modules show
blinking red, green and blue lights alternately. If not, reboot the machine and call HP support reporting
the error appearing at the front panel. If no error is given in the front panel then report “scanner lid
sensor failure”.
2. If all the modules lit up correctly in the previous step, close the scanner lid by pushing it down until you
hear a click. Then calibrate the scanner as indicated in
Scanner maintenance on page 162 and repeat
your scan.
3. If the problem persists, repeat the scan or copy using a higher resolution (High or Max if scanning,
Normal or Best if copying). You should also set background cleaning to 0, or set the content type to
Mixed.
224 Chapter 22 Troubleshooting scan-quality issues ENWW