Minolta CF910 Service Manual page 433

<Troubleshooting Procedure>
Step
11 When comparing the color of the devel-
oper in the Developing Unit with that of the
starter, is the developer color apparently
darker?
12 Open the "Life 3 (Others)" screen from the
"Counter" of the Service mode and check
the figures for "Dev." Is the count around
30K?
13 A. Open the "Background Voltage" screen from "Image Adjust" of the Service
mode. Set the figure to +10 and turn OFF and ON the Power Switch.
B. Using the settings as in step 3, make copies of each color again.
14 Does foggy background persist?
15 Open the "Test Print" screen from the Service mode menu. Select "Halftone" and
set the level to "16" to make copies in each color.
16 Does the foggy background occur at a fre-
quency of one complete turn of the PC
Drum (314 mm)?
17 Open the "Bk Toner Sup. Status" screen
from the "State Confirm" menu of the Ser-
vice mode and check for the figure for "Bk
Constant." Is it 10% or more?
Check Item
T-66
Result
YES Check the wiring between
PWB-I and the Toner Replen-
ishing Motor and, if it is intact,
change the motor.
YES Change the developer.
("Developer" and "Gradation
Adjust")
YES Adjust the "Background Volt-
age" level until the output cop-
ies show no evidence of foggy
background.
(This completes the procedure.)
YES Change the PC Drum.
("AIDC Mode/AIDC Offset" and
"Gradation Adjust")
NO Change the ATDC Sensor and
developer.
("Developer" and "Gradation
Adjust")
If the problem persists after
changing these, change the
Developing Unit.
YES Change the developer.
("Developer" and "Gradation
Adjust")
• If foggy background persists
even after the developer has
been changed, change the
Toner Replenishing Motor
and Developing Unit, in that
order.
NO Go to step 12.
Action