Star Micronics LS-5 SERIES Technical Manual page 125

P-5. Vertical white lines
Print sample
Step
1 (Obstruction of the laser beam path)
Is there any foreign matter or grime in the path of the laser beam
between the ROS assy and the drum?
2 (Faulty BTR assy)
Is there any foreign matter or grime on the BTR of the BTR
assy?
3 (Faulty EPX toner cartridge)
Does the problem stop occurring when the EPX toner cartridge
is replaced with a new one?
4 (Scratches on the heat roll)
Are there any scratches in the circumferential direction of the
heat roll?
5 (Problem with paper transport path)
Are there any irregularities such as burrs, foreign matter, or
grime on the paper transport path?
Missing sections of printing
(This refers to printing in which there are white lines where the printing is missing
in the paper transport direction, in solid areas or half-tone areas.)
Check parts with different specifications for problems with usage, defective
installation, breakage, deformation, and adhesion of grime or foreign matter.
• Main parts to be checked:
(1) EPX toner cartridge, (2) BTR assy, (3) Fuser assy, (4) Heat roll
(5) Inlet chute assy, (6) Trans. chute assy, (7) MCU PCB, (8) ROS assy
Check
– 121 –
TROUBLESHOOTING
Symptom
Initial check
Measure (if abnormal)
Remove any foreign matter or grime
obstructing the path of the laser beam
from the ROS assy to the drum.
Replace BTR assy.
Replace EPX toner cartridge.
Replace heat roll.
Replace the pertinent part.