Unsharpness; Gray Background; See - Kyocera FS-1920 Service Manual

(7) Unsharpness.

Causes
1. Defective paper specifications
2. Defective transfer roller installation
3. Defective transfer bias potential
4. EcoPrint setting

(8) Gray background.

ABC
123
Causes
1. Print density setting
2. Defective drum surface potential
3. Grid
4. Developing roller (in the developer)
Causes
1. Defective paper specifications
2. Defective transfer roller installation
3. Defective transfer bias potential
4. EcoPrint setting
Paper with rugged surface or dump tends to cause unsharp printing.
Replace paper with the one that satisfies the paper specifications.
The transfer roller must be supported by the bushes at the both
ends. Clean the bush to remove oil and debris. Replace the transfer
roller if necessary. See page 1-6-15.
Check the transfer bias output on the high voltage unit. This requires
removal of the left cover and the test equipment. Replace the high
voltage unit if high voltage potential is not available on the board.
See page 1-6-23.
The EcoPrint mode can provides faint, unsharp printing because it
acts to conserve toner for draft printing purpose. For normal printing,
turn the EcoPrint mode off by using the operator panel. For details
refer to the printer's user's manual.
Causes
1. Print density setting
2. Defective drum surface potential
3. Grid
4. Developing roller (in the developer)
The print density may be set too high. Try adjusting the print density
using the Remote operation panel utility. For details refer to the
printer's user's manual.
The drum surface potential should be approximately 230±15 V. This
may vary depending on production lots. Measurement is possible
only by using the jig and tool specifically designed for this purpose.
The drum unit will have to be replaced if it bears values far out of the
allowable range.
Clean the grid by grid cleaner. For details refer to the printer's user's
manual.
If a developer which is known to work normally is available for check,
replace the current developer in the printer with the normal one. If
the symptom disappears, replace the developer with a new one.
See page 1-6-2.
Check procedures/corrective measures
Check procedures/corrective measures
2FP/2FY/2FR
1-5-19