Product

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

Symptoms

Plate exposure appears to proceed without problems. Then, either before or after processing, hot spots (rounded or feathered whitish areas) appear on the plate.

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 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 explain the proper preventative maintenance to the customer and emphasize the importance of performing preventive maintenance regularly.

4. Inspect both 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 5. If you find signs of any of these:

   1. Verify whether this is a new machine. 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.
5. 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. 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.
6. 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.
   • Clean the unload tray rollers using a lint-free cloth.
7. 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.
   • Clean the unload rollers with a lint-free cloth.
8. 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.
9. 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.
      • Clean the loading rollers using a lint-free cloth.
10. Inspect the damaged plate(s), and the plate batch being used. Look for:
    • Defects or dirt: May indicate manufacturer’s defect or damage that was caused to the plate during handling. If found:
    • Load new, clean, undamaged plates. If the problem persists, proceed to the next step.
11. 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.
12. 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 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.
13. 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.
14. 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.
15. 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.
16. 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).
17. 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.
18. Perform the steps described in 'Before You Finish'.

See also

Paper Loads With Plate (pdf)

Technical contact(s)

Itai Peperovich

Submitted by

Boris Gendlesman

Date submitted

04 Jul 2002