Digital Equipment LSR 2000, Service Manual

Page: 299 / 427

6: Troubleshooting Procedures
6-26
Colorwriter LSR 2000 Printer
Service Guide
Transfer sheet 7 Does the print image darken
when you replace the transfer
sheet? YES Replace the transfer sheet.
Poor contact 8 After cleaning the developing
bias-use contact and the toner
cartridge contact, does the
image density improve when
you print a test pattern? YES Clean the contacts and
ensure their connections.
High-voltage power supply
PCB
Mechanical controller PCB
NO Replace and check in the
following order:
• High-voltage power
supply PCB
• Mechanical controller
PCB
Table 6-5 Image defect—dark
Cause Step Check Decision Action
1 Does it improve when you
adjust the image density? YES Operate the external
device or Density Control
Panel to adjust the density.
Density sensor unit 2 Is the lens of the density sensor
unit dirty? YES Clean it with the
designated brush.
Poor contact 3 After cleaning the drum
grounding use contact and the
cartridge contact, does the
image density improve when
you print a test pattern? YES Clean the contacts and
ensure their connections.
Poor contact 4 After cleaning the primary
charging voltage-use contact
and the drum cartridge contact,
does the image density improve
when you print a test pattern? YES Clean the contacts and
ensure their connections.
High voltage power supply
PCB (Primary charging
voltage)
Mechanical controller PCB
NO Replace and check in the
following order:
• High-voltage power
supply PCB
• Mechanical controller
PCB
Table 6-4 Image defect—light (continued)
Cause Step Check Decision Action