Star Micronics LS-5 SERIES Technical Manual page 128

TROUBLESHOOTING
P-8. Horizontal black lines
Print sample
Step
1 (Faulty grounding of the drum)
Has the drum of the EPX toner cartridge been securely grounded?
[Grounding route]
↔
Drum Pin of drum shaft
harness assy HVPS
2 (Faulty HVPS CR (DC))
Is the output of the HVPS CR (DC) normal?
3 (Faulty HVPS DB)
Is the output of the HVPS DB normal?
4 (Faulty BTR assy)
Is there any foreign matter or grime on the BTR of the BTR
assy?
5 (Faulty EPX toner cartridge)
Does the problem stop occurring when the EPX toner cartridge
is replaced with a new one?
6 (Faulty heat roll)
Are there any scratches, foreign matter, grime, or other irregu-
larities on the heat roll?
7 (Noise)
Black lines in print
(This refers to printing in which lines appear in the direction perpendicular to the
paper transport direction. The width of the lines in this case is less than 1 mm.)
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
– 124 –
Symptom
Initial check
Measure (if abnormal)
Make sure there is good conductivity
along the grounding route.
↔ ↔
HVPS
To section 3-18
To section 3-19
Replace BTR assy.
Replace EPX toner cartridge.
Replace heat roll.
To section 3-21