View Full Version : Konica Minolta C6501 - C4501 / C4502 error code

Custom Search

02-02-2011, 10:52 AM
Please could someone help me, i am getting codes C4501 / C4502, replaced both write units and did the write unit initial position prodcedure, ld bias, i/o check, etc. checked the ICP's with board out and machine on, wiped all dev or toner off the dev units, replaced the color registration sensor assy, checked the transfer belt is not scew, am stuck!

02-03-2011, 12:37 AM
The following TSBs entries may be of value in this issue

C-2211, C-2212, C-2213 or C-2214usually when the machine is running in Thick Paper mode (1/2 line speed). These are drum drive error codes.


1. Incorrect drum speed.
Please instal minimum version 40 firmware to correct the drum speed.The latest version firmware is available via the Konica Minolta Download Selector. Access the Selector from SSD Web Support (CS Expert Support) by clicking on 'Download MSDS, Drivers, Firmware and more'. After installing the firmware please set the following DIP SW to the recommended setting:

bit 6 bit 7
0 0 Default
1 0 0.1% up
0 1 0.2% up (Recommended)
1 1 0.3% up

If the symptom reoccurs with the recommended value, try the 0.3% UP setting.

2. Cleaning blade has "flipped" on a corresponding color.

3. Incorrect Belt Line Speed Adjustment setting.
Check the setting by referring to section 10.3.8 Belt Line Speed Adj. (Printer Adjustment) in the Service Manual. If the setting value is not in the range between -5 to -35, readjust the value within -5 to -35. If -5 to -35 cannot give the satisfactory result, also perform the section 10.3.3. FD Mag. Adjustment (Printer Adjustment).

4. Failed Drum Drive Unit.
Replace the Failed Drum Drive Unit (p/n A03U R757 00 for Yellow / Cyan ) and p/n A03U R758 00 for Black / Magenta ).

C-4520 error code at power up. With poor copy quality, lines, wrinkles. The transfer belt may mis-track or slide toward one side or the other ("walking" off the rollers) during color registration adjustment, after performing a PM.

possibly with C-2714 error code. No image is visible on the transfer belt.
possibly with C-4501, C-4502, C-4503 and/or C-4504 error codes.
possibly with C-4521 and/or C-4522 error codes.


At power up

CAUSE: Ten (10) pixels of Color registration overlap is detected when comparing to a previous Color Registration adjustment.

SOLUTION: In order to reduce the error occurrence ratio, the following function was added to firmware version 60.

DIP SW 23-1
0 : SC detected condition 10 pixels (Default)
1 : SC detected condition 60 pixels


1. To change SC detected condition only, color registration accuracy itself is not change.

2. The purpose of this DIP switch is to reduce the occurrence ratio. Color registration problem itself cannot be improved.

3. Download and install firmware version 60 if necessary. The latest version firmware or system software is available via the Konica Minolta Download Selector. Access the Selector from SSD Web Support (CS Expert Support) by clicking on 'Download MSDS, Drivers, Firmware and more'. Poor copy quality, lines, wrinkles. The transfer belt may mis-track or slide toward one side or the other ("walking" off the rollers)


1. Upper front bearing falling out of the holder because of lack of tension on the upper roller bearings. Remove and reverse the upper front bearing (p/n 5400 7605 0 listed on page 32, Key 5 in the Parts Manual) so that the bearing flange is outward and/or slightly re-form the holder in which it sits so that more pressure is applied to the bearing.

2. Tension roller in the Intermediate Transfer Assemblybecoming dislodged, permitting the transfer belt to “walk off” or the upper and lower tension rollers are not lining up correctly. Addition of a new spacer at each end of the tension roller prevents the roller from disengaging from the bracket. To accommodate the new spacer, the length of the roller has been increased slightly and a “D” shape placed on the ends. Also, adjusting the lower tension roller is suggested.

3. Gaps between Tension Plate Rear Caulking (p/n 65AA -273 0) and Plate/Rear (p/n 65AA 2625 0E) after maintenance performed on the transfer belt unit. Set Tension Plate Rear Caulking properly so that no gap exists and firmly fix with screw.

During color registration adjustment


1. Failed color registration sensor PS8 or PS9. To identify the failed sensor, you can swap PS8 with PS9. Run Output Check, code 5, multi code 2 for Color registration sensor output voltage or code 5, multi code 6 for Color registration sensor. A number between 0 and 255 is displayed on the [IN] area of the LCD. Inspect the Color Compensating wiring connecting each sensor to a CRB.The Color Registration assembly (p/n A03U R798 00) will need to be replaced if PS8 or PS9 has failed.

2. PS8 and PS9 not calibrated properly.

To calibrate:

a. Disable Color Registration Correction Control in the 25 mode, software DIP switch 25, bit 3 to 1 (ON) and bit 4 to 0 (OFF).

b. Run Color Registration Adjustment in the Service Mode ? Machine Adjustment ? Printer Adjustment ? Color Registration Adj.

c. Enable Color Registration Control in the 25 mode, software DIP switch 25, bit 3 to 0 (OFF) and bit 4 to 0 (OFF).

d. Perform Auto Color Registration adjustment again.

After performing a PM

CAUSE:The Color Registration adjustment was not performed

SOLUTION: Perform the Color Registration adjustment:

1.Enter Service Mode.
2.Select Machine Adjustment.
3.Select Printer Adjustment.
4.Select Color Registration Adjustment and then Start.
5.Exit Service mode.

Possibly with C-2714 error code. No image is visible on the transfer belt.

CAUSE: The first transfer pressure release motor (M19) coupling gear is spring loaded and can become lodged in the back position.

SOLUTION: Release the first transfer pressure release motor (p/n 08AA 8003 0) coupling gear (p/n 65AA 1714 0) so that it springs freely when pressed and released.

Possibly with C-4501, C-4502, C-4503 and/or C-4504 error codes.


1. Open ICP fuse on the Printer Control Board (PRCB). Check the continuity of the ICP fuses ICP17, ICP20, and ICP21 with the PRCB out of the machine. You can also carefully check that there is 24V DC on each side of the fuses while the board is in the machine. Voltage on just one side of the fuse would indicate that the fuse is open and the board needs replacing (p/n A03U R75911 - Printer Control Unit).

2. If [09 Writing Init. Pos. Memory] is not performed, the adjustment value is not reset to the initial value. Consequently, adjustment margin is decreased in some cases. When the write unit is replaced, clean the dust-proof glass and perform the following adjustments in order:

a. Writing Init Pos. Memory
b. LD Bias Adjustment
c. I/O check mode
d. CD Skew Adjustment
e. Restart Timing Adjustment
f. Color Registration Adjustment
g. Color Registration/Manual (Adjustment)
h. Auto Gamma Adjustment

Possibly with C-4521 and/or C-4522 error codes

CAUSE: ICP17 is OPEN on the Printer Control Board. The wiring between the printer control board and the hardware counters may be pinched. If the wire is shorted to ground, ICP17 on the printer control board will open, resulting in the error code. If the wire is broken internally without shorting, the machine will function but the counter will not increment.

SOLUTION:Check the wiring between the PRCB and the Total Counter. There might be a short to ground close to the Total Counter. After the short is found and repaired, replace the PRCB (p/n A03U R759 11).

If the wiring is not damaged, reposition it so that it is secured in the plastic hooks behind the counters. This will keep the wiring from being pinched when the cover is removed and reinstalled. It is recommended that all machines be inspected at setup or the next service call to prevent future incidents.

C-4501 yellowlaser correction failureoccurs after running the "Both Sides" paper tray adjustment.


CAUSE: The error occurs because the adjustment was not completed prior to running test copies.

SOLUTION: To correct the problem, perform the following procedure:

1. Select the Machine icon on the control panel.
2. Select the Both Sides icon on the lower part of the control panel.
3. Input the paper tray adjustment values.
4. Select Chart Adjust.
5. Select Adjustment Start.
6. Select Close after the adjustment completes.
7. Select the Copy icon and run test copies.

02-07-2011, 06:55 AM
I have tried all the procedures attached above - no joy?? any thing else i can try??

06-21-2011, 04:58 PM
have you check the wiring between the printer control board and the write unit may be pinched, if you have try all that mention above, better you try to replace PRCB.

Custom Search