Star Micronics LS-5 SERIES Technical Manual page 121

P-1. Light
Print sample
Step
1 (Humidity and wrinkling of the paper)
Does the problem occur even if the paper is replaced with new
paper?
2 (Defective grounding of the drum)
Has the drum of the EPX toner cartridge been grounded
securely?
[Grounding Route]
↔
Drum Pin of drum shaft
harness assy HVPS
3 (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?
4 (Faulty HVPS DB)
Is the output of the HVPS DB normal?
5 (Faulty BTR assy)
Is there any foreign matter or grime on the BTR of the BTR
assy?
6 (Faulty image transfer)
Is the toner image on the drum transferred correctly to the
paper?
• Try turning off the power at the point in printing when you
think the image is being transferred to the paper, and check
the image on the drum.
7 (Faulty EPX toner cartridge)
Does the problem stop occurring when the EPX toner cartridge
is replaced with a new one?
Printing is too light.
(This refers to printing in which the density of the overall image is lower than the
standard density.)
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) HVPS, (3) Earth plate assy, (4) BTR assy
(5) Trans. chute assy, (6) Wire assy TR, (7) MCU PCB
(8) Harness assy HVPS, (9) LVPS assy, (10) Fuser assy, (11) ROS assy
Check
↔
earth plate assy
↔ ↔
MCU PCB LVPS assy
– 117 –
Symptom
Initial check
Measure (if abnormal)
Replace paper.
(Request that the customer store the
paper in a location where there is low
humidity.)
Make sure there is good conductivity
along the grounding route.
↔ ↔
HVPS
Remove any foreign matter or grime
obstructing the path of the laser beam
from the ROS assy to the drum.
To section 3-19
Replace BTR assy.
To section 3-20
Replace EPX toner cartridge.
TROUBLESHOOTING