Home | Contact Us | Submit Troubleshooting Info | Search | Help


    Output | Software Solutions | Proofing | Color, Screening and Calibration | Scanning | Digital Photography | Consumables | POS


Pressure Marks on Plates Outputted by the Lotem 800


Product

 
  • Lotem™ 800 (S-speed)
  • Lotem 800 (F-speed)
  • Lotem 800 Quantum
  • Lotem 800 with Spectrum

Symptoms

 

Plate loading and unloading appears to proceed without problems. Then, either before or after processing, pressure marks appear on the plate.


Cause

  Probable causes include the following:
  • Expired plate batch
  • Damaged or deformed plates
  • Processor problems
  • Cassette exit roller malfunction
  • Disposal system roller malfunction
  • Unloading roller malfunction
  • Loading roller malfunction
  • Actuator piston malfunction

Solution

 

This section includes a detailed troubleshooting procedure. If at any point you feel that you have found the source of the problem, you can either process several plates to verify that the problem has been resolved, or you can continue to the end of the procedure.

  1. Keep the damaged plates.
  2. Review all generic troubleshooting questions with the customer.
  3. Check the gauge on the wall air pressure unit. Verify that the pressure level is not less than 6 bar and that it is constant. If it is not:
    • Adjust the air pressure level.
    • If the problem persists:, answer all generic troubleshooting questions and then, contact your service representative.
      • Check the air pressure requirements.
      • Replace the air filter system, as required.
  4. Check the expiration date on the plate packaging.
    • If the expiration date has passed, load and process a fresh batch of plates.
    • If the expiration date has not passed, or if the problem persists, proceed to the next step.
  5. Inspect the damaged plate(s) and the plate batch being used. Look for defects or dirt. If found, load new, clean, undamaged plates.
    Note: This may indicate manufacturer’s defect, or damage that was caused to the plate during handling or storage. If the conditions in the plate storage room do not meet product guidelines, consult the plate supplier.
  6. Expose an additional plate.
  7. Rotate the plate by 90° and perform plate processing.
  8. Inspect the processed plate and compare it to the plate on which pressure marks were originally found. If pressure marks are found:
    • Positioned at a 90° angle to the pressure marks originally found, perform steps 9, 10 and 11.
    • Positioned exactly as the pressure marks originally found, proceed to step 14.
  9. Check the chemicals currently being used in the processor. Verify that they are:
    • Compatible with the plates being processed, as described in the manufacturer's guidelines. If they are not, replace the chemicals with a compatible brand and type.
    • Fresh. Check the expiration date on the original container. If the date has passed, replace the chemicals with a fresh batch.
  10. Visually inspect all of the processor entrance rollers. Look for dirt, debris and/or foreign objects. If found:
    • Remove any debris and/or foreign objects.
    • Clean the entrance rollers.
      Note: For details, refer to the user documentation for your processor.
  11. Verify whether the following are calibrated appropriately:
    • Processor temperature.
    • Processing speed.

    If they are not calibrated appropriately:

    • Adjust the calibration as required. Then expose another plate and process and inspect it as described in steps 7 and 8.
    • If the problem persists, contact the appropriate processor service representative.
  12. Load and expose an additional plate. Do not unload the plate.
  13. Open the rear door. Then, manually rotate the drum and inspect the plate for pressure marks. If no pressure marks are found, answer all generic troubleshooting questions and then, contact your service representative.proceed to step 15.
  14. Inspect the size and shape of the pressure marks that were originally found on the plate. If the pressure marks are:
    • Small and round (resembling pinholes), and repeat at regular intervals in a line running from the leading edge of the plate to the tail edge, answer all generic troubleshooting questions and then, contact your service representative.the marks are probably caused by the loading and/or unload rollers. Remove the assemblies and check the rollers and springs. If a 1.1 mm spring assembly is installed (P/N 290A4L268), replace it with a 1 mm spring assembly (P/N 290A6A319).
    • The width of the cassette exit rollers, proceed to step 20.
    • Any other width, and appear as one or more lines running from the leading edge of the plate to the tail edge, proceed to the next step.
  15. From the rear of the machine, inspect the unload tray rollers. Look for:
    1. Oil, grease, dirt, and/or debris. If found, remove any debris, and clean the rollers with a lint-free cloth.
    2. Damage or wear. If found:, answer all generic troubleshooting questions and then, contact your service representative.
      • Install new unload tray rollers and then,
      • Clean the unload tray rollers using a lint-free cloth.
  16. Inspect the unload rollers. Look for:
    1. Oil, grease, dirt, and/or debris. If found, remove any debris, and clean the rollers with a lint-free cloth.
    2. Damage, worn or missing rollers, protruding springs and/or restricted roller movement (turn each roller with your finger). If found, answer all generic troubleshooting questions and then, contact your service representative.:
      • Install new unload rollers and then,
      • Clean the unload rollers with a lint-free cloth.
  17. Inspect all the rollers in the upper gripper actuator assembly. Look for:
    1. Oil, grease, dirt, and/or debris. If found, remove any debris, and clean the rollers with a lint-free cloth.
    2. Damage, worn or missing rollers, protruding springs and/or restricted roller movement (turn each roller with your finger). If found:
      • Install new rollers and then,
      • Clean the rollers using a lint-free cloth.
  18. Inspect the loading rollers. Look for:
    1. Oil, grease, dirt, and/or debris. If found, remove any debris, and clean the rollers with a lint-free cloth.
    2. Damage, worn or missing rollers, protruding springs and/or restricted roller movement (turn each roller with your finger). If found:
      • Install new loading rollers and then,
      • Clean the loading rollers using a lint-free cloth.
  19. Adjust the distance traveled by the actuator piston to reduce the amount pressure exerted by the load/unload rollers, as follows:
    1. Open the right side door and, on the manifold, press the button on the relevant solenoid to activate the piston.
    2. Adjust the piston potentiometer to reduce the pressure, as required.
  20. Inspect the cassette exit rollers. Verify that the rollers are completely clean and free of debris (turn them with your hand). If they are not:
    • Remove any debris, as required.
    • Clean the rollers using a lint-free cloth.
  21. Check the date on which the drum was last cleaned. Then, inspect the entire drum for dirt and/or debris. If found:
    1. Remove debris, as required.
    2. Clean the drum using a lint-free cloth dampened with alcohol.

    Note: This may indicate that Preventive Maintenance is not being properly and/or regularly performed. Please instruct the customer as to the proper method. Also, please emphasize the importance of performing Preventive Maintenance regularly.

  22. Inspect the drum vacuum holes, and the vacuum channel near the vacuum holes. Look for signs of:
    • Oil
    • Grease
    • Moisture
    • White powdery substance

    If you don't find any of the above, proceed to step 23. If you find signs of any of these:

    1. Verify whether the machine is new. If it is:
      • Thoroughly clean the drum vacuum holes.
      • Thoroughly clean the drum vacuum channels.
      • Clean the drum using a lint-free cloth dampened with alcohol.
        Note: Use an oilstone to remove any stubborn substances.
    2. Check the filter in the wall air pressure unit and verify that it is clean. If it is not:
      • Change the filter in the wall air pressure unit. Click here for important, additional information.

        Note: This may indicate that Preventive Maintenance is not being properly and/or regularly performed. Please instruct the customer as to the proper method. Also, please emphasize the importance of performing Preventive Maintenance regularly.

      • Purge the air supply.
      • Thoroughly clean the drum vacuum holes.
      • Thoroughly clean the drum vacuum channels.
      • Clean the drum using a lint-free cloth dampened with alcohol.
        Note: Use an oilstone to remove any stubborn substances.
  23. Further inspect the drum vacuum holes for dried epoxy that is not flush with the drum surface.
    Note: To facilitate secure plate attachment, some of the drum vacuum holes may have been filled in with epoxy. If the dried epoxy is not filed down to be flush with the drum surface, it may cause hot spots.
  24. If found, answer all generic troubleshooting questions and then, contact your service representative.file down the dried epoxy until it is smooth and flush with the surrounding area.

  25. Open the front door and inspect the XY bar paper clips. Verify that:
    • The paper clips are not stuck and that they open fully. If the paper clips are stuck and/or do not open fully due to a build-up of dirt, clean the paper clips with a lint-free cloth.
    • The paper clips are not stuck due to being bent, and that there is no damage to the rubber tips. If any part of one or more of the paper clips is bent, or if there is any damage to the rubber tips, answer all generic troubleshooting questions and then, contact your service representative.replace the paper clips. Do not attempt to bend or otherwise adapt the paper clips.
  26. Visually inspect the disposal system rollers (both rows). Verify that the rollers are completely clean and free of debris (turn them with your hand). If they are not, remove any debris, and clean the rollers with a lint-free cloth.
  27. From the front of the machine, shine a flashlight on the plate support rollers (on the punch beam) and, along the line of the hot spots, visually inspect the rollers. Verify that:
    • The rollers are completely clean and free of debris (turn them with your hand). If they are not, remove any debris, and clean the rollers with a lint-free cloth.
    • The rollers are not damaged in any way. If they are, answer all generic troubleshooting questions and then, contact your service representative.replace the plate support rollers.
  28. Visually inspect the plate leading rollers. Verify that they are completely clean and free of debris (turn them with your hand). If they are not, remove any debris, and clean the rollers with a lint-free cloth.
  29. Close all doors, as required. Then, perform plate loading to verify whether the problem is resolved.
    Note: Be sure to use undamaged plates (inspect the plates before loading them into the cassette).
  30. Insert the open cassette into the machine, leave the front door open and, using a cheater, perform plate loading. Watch the plate as it progresses through the machine.
    Note: If the customer is using a dual cassette, be sure to redefine the cassette as dual loading before leaving the site.
  31. Perform the steps described in Before You Finish.

See also

 

TBD


Technical contact(s)
 

Itai Peperovich

Submitted by
 

Boris Gendlesman

Date submitted
 

28 Aug 2002



Popups / Tool Tips for this Page

   Close this popup...   To inspect the drum:

  1. Open the rear door and, from the rear of the machine, manually turn the drum until the tail gripper is accessible.
  2. Manually move the tail gripper to the pre-load position (as shown in the label on the upper panel of the machine—this enables you to thoroughly inspect the drum).

   Close this popup...   To inspect the loading rollers:

  1. Open the rear door, as required.
  2. Remove the rear upper panel.
  3. Remove the unload Tray.
  4. From the rear of the machine, shine a flashlight on the loading rollers (shown below).
  5. Run your hand over the rollers.
  6. Inspect your fingers for signs of oil, grease or moisture.
  7. Visually inspect the rollers for dirt, debris and/or damage such as protruding springs.

   Close this popup...   To inspect the cassette exit rollers:

  1. Remove the cassette from the machine, and open the cassette.
  2. Placed the processed plate in the cassette. Position it exactly the same way it was before exposing.
  3. Turn the plate over so that the leading edge is where the tail edge was and vice versa, and the emulsion side is up.
  4. Look at the pressure mark(s) and visually follow the position of the mark(s) toward the cassette exit rollers, beyond the edge of the plate. Along this line, inspect the cassette exit rollers (shown below).

   Close this popup...

Important!

Check the date on which the air filter was last changed. If it was due to be changed, please insure that it is changed regularly, as described in the user guide. However, if it was recently changed, check the compressor that supplies air to the wall air pressure unit. Verify whether it is functioning properly and providing clean air to the unit. If it is not, contact the person who is responsible for compressor maintenance. Then, when the problem is resolved, purge the air supply.

   Close this popup...   To inspect unload tray rollers:

  1. Open the rear door, as required. From the rear of the machine, inspect the rollers (shown below).

   Close this popup...   To inspect the unload rollers:

  1. Open the rear door, as required.
  2. From the rear of the machine, shine a flashlight on the unload rollers (shown below).
  3. Carefully, so as not to bend the unload roller springs, run your fingers over the rollers.

   Close this popup...   To check the XY bar paper clips:

  1. Manually raise the XY bar, as required.
  2. Use your finger to push the paper clips downward and upward in the XY bar. Verify that they are not stuck, they open
    fully and do not move too freely.
  3. Visually inspect the paper clips (shown below). Verify that they are not bent and/or worn out.
  4. Visually inspect the rubber covering of the paper clips closely to look for tears and/or foreign objects.

    Copyright © 2005 Creo Inc. All rights reserved. Confidential. Back to top.