Oki ML520 - Manual (Page 181)

2. Defective platen. Replace the platen.
Smeared Print
Possible Causes:
1. Ribbon protector is missing or broken. Replace the ribbon protector.
2. Verify that the headgap menu setting is appropriate for the type of paper being used.
3. Check / perform the printhead gap adjustment.
4. Paper is not within specification. Refer to Section One for paper specification.
Inconsistent Line Feed
Possible Causes:
1. Power OFF the printer. Turn the platen knob. The platen should rotate smoothly. If it does not, remove
the cause of the binding.
2. Defective line feed motor. Replace the line feed motor.