P-7: Ng (M Developing Unit Failure - Minolta CF910 Service Manual

(7) P-7: NG (M Developing Unit Failure)

Step
1 Select "Test Print" from the Service mode menu. Select "Gradation Pattern" and
then "4 Color"; then, press the Start key.
2 How is the output image?
3 Was the Developing Unit making noise
during the test print?
4 Is the connector of Developer Supply
Clutch (M) CL18 properly connected?
5 Is the CL18 ON signal being output from
PJ2I-7A on PWB-I?
6 A. Open "Developer Change Mode" and then "ATDC Sensor Adjust (Auto)." Turn
ON Magenta and press the Start key.
B. Check the ATDC output value.
7 Does the ATDC Sensor output value show
4% or less?
8 A. Open "Image Adjust" and then "ATDC Toner Supply." Select Magenta and
press the Start key.
Note:
Remove the exterior cover from the Hopper before executing the toner supply,
as the Hopper operation must be checked in step 9 that follows.
9 Is the Hopper energized during toner sup-
ply in step 8?
10 Is the ATDC Sensor window seriously
contaminated with developer?
Check Item
T-97
Result
• No image: To step 3.
• Extremely low image den-
sity: To step 6.
• Extremely dark image den-
sity: To step 12.
YES Check the drive for possible
overload.
NO Reconnect the connector.
YES Check the wiring between
PWB-I and CL18 and, if it is
intact, change CL18.
NO Change PWB-I.
NO Go to step 10.
YES Change the Developing Unit.
("Developer Change Mode,"
"Gradation Adjust")
If the malfunction code persists,
change PWB-I.
NO A. Check the wiring between
PWB-I and Toner Replen-
ishing Motor (M) M11.
B. Check the motor drive for
possible overload and, if it
is free of overload, change
M11.
C. If A. and B. have been
checked okay, change
PWB-I.
YES Change the Developing Unit.
("Developer Change Mode,"
"Gradation Adjust")
Action