Minolta CF910 Service Manual page 452

<Troubleshooting Procedure>
Step
11 Does the problem persist even after the
Transport Unit has been changed?
12 Open the "ATDC Sensor" screen from the
"Machine Adjust" menu of the Service
mode and check the sensor outputs for C,
M, and Y.
Is there any reading of 4% or less?
Open the "Bk Toner Sup. Status" screen
from the "State Confirm" menu of the Ser-
vice mode.
Is the figure for "Bk Constant" 3% or less?
13 Is the Hopper, which has been considered
to develop a faulty I.D., loaded with toner?
14 Open the "ATDC Toner Supply" screen from the "Developer" menu of the Service
mode and press the Start key.
Note: Remove the exterior cover from the Hopper before executing the toner supply.
Reason: The operation must be checked in step 15 that follows.
15 Is the Hopper properly energized when
toner supply is executed in step 14?
16 Does the user usually use originals with
high black-to-white ratios?
17 Is the ATDC Sensor window seriously
contaminated with developer?
18 Is there continuity between the GND of the
ATDC Sensor and the shaft of the Devel-
oping Unit?
Check Item
T-85
Result
YES Change the Polygon Motor
Drive Board, PWB-JA, and -JD,
and PH Upper and Lower Units
as a set. ("IR Area," "PRT Area,"
and "Gradation Adjust")
NO This completes the procedure.
NO Go to step 17.
NO Replenish the supply of toner.
NO Change the Hopper.
If a replacement unit is not
readily available:
A. Increase the ATDC level by
1 to 2%.
B. Run "ATDC Toner Supply" of
"Developer."
YES A. Open the "ATDC Sensor"
screen from the "Developer"
menu and increase the level
by 1 to 2%.
B. Run "ATDC Toner Supply" of
"Developer."
NO Open the "PRT Max Density"
screen from the "Image Adjust"
menu and increase the level by
1 to 2%. In this condition, turn
OFF and ON the Power Switch.
YES Change the Developing Unit.
("Developer" and "Gradation
Adjust")
YES Change the ATDC Sensor and
developer.
("Developer" and "Gradation
Adjust")
NO Change the Developing Unit.
("Developer" and "Gradation
Adjust")
Action