The following simple rules can help in finding potential defects that can be shown during the copy quality control:
- If the copy has vertical stripes from the upper to the lower border of the sheet, the defect could be due to:
- The optical system is not perfectly cleaned.
- The cleaning blade is not properly working because of low quality of the polyurethane rubber.
- The quality of the toner is poor and it causes toner deposit on the blade.
- If the defect shown on the copy gets larger when the copy is enlarged or smaller when the copy is reduced, almost certainly the problem is due to a defective optical system (clean and check carefully the optical system of the machine).
- The appearance of horizontal white bands is probably due to a defective scanner. On the other hand the presence of dark horizontal bands indicates a rotation problem of the drum or a paper transport problem due to defective gears, belts or paper feed tyres.
- If the defect on the copy is repeated in the same page, the distance at which the defect occur can correspond to the diameter of one of the cylindrical parts (fusing roller, drum or development roller…etc.) This part must be checked carefully and, if necessary, repaired or replaced