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Print Quality Problems

Many print quality problems are directly related to the kind of forms that are being used and the application that is being processed. If a particular form or application regularly produces unsatisfactory output, refer the application owner to the Forms Design Reference for Continuous Forms Advanced Function Printers, G544-3921. This publication contains detailed information about selecting forms and designing applications for use with continuous forms printers.

Table 18 describes possible print quality problems and suggests actions that may correct the symptoms.

Table 18. Print Quality Symptom Table
Symptom Action
Poor fusing

If poor fusing occurs on labels or heavy forms, increase the preheat temperature (see Setting/Adjusting the Preheat Platen Temperature) until the fusing is acceptable. Run several hundred feet of forms to stabilize the temperature. Check the fusing to see if it is acceptable.

Continue to increase the preheat temperature value and try printing again until fusing is acceptable.

If adequate fusing does not occur, set the preheat temperature value to the default value of 0 (zero). Increase the hot roll temperature (see Setting/Adjusting the Hot Roll Temperature) and try printing again until the fusing is acceptable.

If adequate fusing does not occur, the form may be unacceptable for use on the printers.

Examine the printed forms in the stacker to verify that the sheets are not sticking together, or that toner is not being pulled off adjacent sheets. If either condition exists, the form may be unacceptable for use on the printers. Evaluate the condition of the printed forms and consider the following:

  • How long it took to print the job
  • How long the forms were left in the stacker
  • How much pressure was applied to the stack
  • The type of application for which the forms are used, for example, bar-code readability.
Forms stick together
  • If forms stick together or toner is pulled off the forms in the stacker, decrease the preheat temperature (see Setting/Adjusting the Preheat Platen Temperature). Run several hundred feet of forms to stabilize the temperature. Check the fusing to see if it is acceptable.
  • If the fusing is acceptable but forms stick together in the stacker, decrease the preheat temperature value and try printing again. If adequate fusing does not occur without forms sticking together, the forms may be unacceptable for use on the printers.
  • Adjust the Contrast value using the Forms Characteristics box (see Setting/Adjusting the Contrast) to the lowest possible setting that produces acceptable print quality. If this is a duplex printing system, remember to adjust the contrast setting on both printers so that the contrast is balanced between the front and back side of the forms.
  • Increase the Oil Rate (see Setting/Adjusting the Oil Rate). (If the oil rate value is currently set to the default value 0, determine the actual default value by looking at Oil Rate in Printer Configuration.

    Print several hundred feet of forms and check the forms in the stacker. If the forms still stick together, increase the oil rate0 again and try printing.

    Check the fusing to see if it is acceptable; if it is not acceptable, return the Oil Rate to the previous setting. Increasing the print contrast may also improve fusing of solid areas and bar codes.

Heat damage with the printer running

If heat damage (melting or curling) occurs to forms or labels while the printer is running, set both the Preheat and Hot Roll temperatures to lower values and try printing again. Always use the lowest preheat and hot roll temperature values that produce acceptable fusing.

Repeating spot patterns
  • Clean the printer and the oil belt. See Cleaning the Printer and Cleaning the Oil Belt.
  • If the oil belt is excessively dirty with toner, increase the speed of the oil belt for that specific form (see Setting/Adjusting the Oil Belt Speed).
  • If you have been running labels, print a test job on plain paper forms to remove any adhesive residue that the labels may have left in the printer.
Print is too dark or characters appear too wide. Press the Lighter Contrast Control key on the printer control panel.

To save the new contrast setting for this form, see Setting/Adjusting the Contrast.

In duplex printing mode, there is a noticeable difference in the printing contrast between the front and back sides of the form, even though the Contrast Switch setting is set the same on both printers. It is normal for printing contrast to vary between printers. Adjust the Contrast setting on the printer control panel of both printers to balance the contrast between the printers.

To save the new contrast setting for this form, see Setting/Adjusting the Contrast.

Blank spots (voids) or light areas appear near perforations. This problem is usually related to forms design, and it cannot be corrected by adjusting the printer.

The following restrictions, copied from the Forms Design Reference for Continuous Forms Advanced Function Printers, G544-3921 must be maintained.

Print quality may be poor near fold perforations, an internal perforation, or any cut in the form. To ensure correct operation and print quality, maintain the following distances:

  • From non-folding and internal perforations: 1.27 mm (0.05 in.)
  • From folding perforations: 1.27 mm (0.05 in.)
  • From binder holes and cuts: 2.54 mm (0.1 in.)

If the specified distance from the page perforations is not being maintained, refer the application owner to the Forms Design Reference for Continuous Forms Advanced Function Printers, G544-3921.

Loss of edge definition or lighter print contrast (boldness) at the trailing edge of bar codes, shaded or solid fill areas, or formatted bold text characters. The problem can be reduced or eliminated by increasing the Contrast switch setting on the printer control panel. Remember to adjust the contrast setting on both printers when they are in duplex mode This balances the contrast between the front and back of the forms.

To save the new contrast setting for this form, see Setting/Adjusting the Contrast.

Blank spots (voids) or light areas not near perforations
  • Ensure that the forms are smooth and flat. Feel the forms, especially near the perforation. If you find lumps, bumps, or wrinkles, load another box of forms. This kind of problem can be caused by storing forms in a poor environment (for example, high humidity).
  • If you have been running labels, print a test job on plain paper forms to remove any adhesive residue that the labels may have left in the printer.
  • Clean the coronas. See step 24 in "Cleaning the Printer".
  • Press the Darker Contrast Control key on the printer control panel.

    To save the new contrast setting for this form, see Setting/Adjusting the Contrast.

  • If the void or light area is in the shape of an adhesive label, call your service representative. See Service Call Procedure.
Print has white streaks.
  • Clean the coronas. See step 24 in "Cleaning the Printer".

    If necessary, remove the coronas and look for forms chads in the wire or corona housing. Be careful not to touch the wire with your hands. See Cleaning the Printer.

Print is too light.
  • Press the Darker Contrast Control key on the printer control panel.

    To save the new contrast setting for this form, see Setting/Adjusting the Contrast.

  • Clean the coronas. See step 24 in "Cleaning the Printer" and step 10 in " Cleaning the Printer".
  • If you opened and closed the developer drain without replacing the developer mix, replace the developer mix now. Opening the drain resets the developer mix usage timer; this could result in the developer mix being used beyond its normal life and result in immediate print quality problems. See Changing the Developer Mix.
Print rubs off easily.
  • Ensure that the forms were fused. For example, did you use Forms Feed when you should have used NPRO?
  • If print rubs off solid fill areas (logos, bar codes) on the form, press the Lighter Contrast Control key setting on the printer control panel until fuse grade is acceptable. Remember to adjust the contrast setting on both printers, when they are in duplex mode. This balances the contrast between the front and back of the forms.

    To save the new contrast setting for this form, see Setting/Adjusting the Contrast.

  • Increase the Preheat and/or Hot Roll temperatures (see Setting/Adjusting the Preheat Platen Temperature and Setting/Adjusting the Hot Roll Temperature).
  • Clean the oil belt. See Cleaning the Oil Belt.
  • Ensure that the hot roll shield is up.
  • Load a different box of forms. The forms you are running may be too heavy (more than 160 g/m2 (42 lb) when running simplex mode, or more than 105 g/m2 (28 lb) when running duplex mode), or too moist, or have too rough a surface.
  • Ensure that no adhesive labels are on the hot roll.
Print is offset (double images).
Print is not correctly registered.
Dark background or dirty prints
Dark streaks
Dark or fuzzy 12 mm (0.5 inch) wide band across width of page (print bloom); characters appear bolder or slightly larger than normal. This problem may occur at the point where pages stop in the fuser. The problem may also be application-related, and if so, cannot be corrected by adjusting the printer.
Any other print quality problem or any of the above problems that persist after you have followed all of the corrective steps. Call your service representative. See Service Call Procedure.