Can you clean the laser mirrors

Possible remedies for weak images.
-Loose connection between transfer roller and high voltage supply unit.

-Dust in the laser beam path

-Transfer belt not contacting PCU.

Check the transfer unit.

Defective PCU. Replace the PCU.

Defective transfer roller. Repair the transfer roller.

Defective fusing unit. Replace the fusing unit.

Defective engine board. Replace the engine board.

In my experience, the fuser has always been the cause of the lines.

P-21 - Color regist test pattern failure
• The number of points detected in the main scan direction is more or less than the specified value during main scan direction registration correction.
• The number of points detected in the sub scan direction is more or less than the specified value during sub scan direction registration correction.
P-21: Color regist test pattern failure
Relevant parts:
• Transfer belt unit
• PH unit
• Printer control board (PRCB)
Step/Action:
1/ Wipe clean the surface of the transfer belt with a soft cloth, if it is dirty.
2/ Change the image transfer belt unit if the transfer belt is damaged.
3/ Change the PH unit.
4/ Change PRCB.
(See Service Manual, pages 599, 603):
http://www.imcopexamerica.com/service-books/Bizhub/Color/bizhubC451_C550_C650FieldSvc.pdf

See also here:
Konica Minolta Bizhub c451 Reparacin de Fotocopiadoras YoReparo
Thread Problemas na C451 7 21

1 Wipe clean the surface of the transfer belt with a soft cloth, if it is dirty.
2 Change the image transfer belt unit if the transfer belt is damaged.
3 Change the PH unit.
4 Change PRCB.
Hope fully not the last two expensive.

This is a ITB contact motor error.
Check/clean/replace contact sensor.
Replace transfer belt contact motor.
Check harness and connectors to motor and sensor.
Check for mechanical binds.

P-21: Color regist test pattern failure




1 Wipe clean the surface of the transfer belt with a soft cloth, if it is dirty.
2 Change the image transfer belt unit if the transfer belt is damaged.
3 Change the PH unit.
4 Change PRCB.

run halftone prints from service mode to isolate which color is having an issue.

check all image units

P-21: Color regist test pattern failure




1 Wipe clean the surface of the transfer belt with a soft cloth, if it is dirty.
2 Change the image transfer belt unit if the transfer belt is damaged.
3 Change the PH unit.
4 Change PRCB.

run halftone prints from service mode to isolate which color is having an issue.

check all image units

Check on you drim uint the gears damaged.

The SC 326 is -- 2nd laser synchronization error. Meaning, the 2nd laser synchronization signal cannot be detected by the main scan synchronization detector board even if the laser diodes are activated.

Basically your polygonal mirror motor unit is bad and needs to be replaced. You can replace the whole laser unit but that is expensive. When you replace the PMM unit, do so in a still air area -- as to not get anything in the unit. When you get the PMM unit -- contact me and I can walk you through the steps to replace.


The SC 452 is --- Transfer Belt Mark Detection Error. Once you fix the SC 326 error this one should be fixed also.

The following is taken from the service manual I hope it helps Thanks J


SC457 Position error for
the image
transfer belt’s
cleaning unit
- Timing & Condition
• When the belt cleaning
section touches the
image transfer belt, but
the belt cleaning sensor
signal remains LOW.
• When the belt cleaning
section releases from the
image transfer belt, but
the belt cleaning sensor
remains HIGH.
• Dirty Sensor
• Defective sensor
• Defective belt cleaning
shift clutch
• Defective drum
peripheral component
motor
• Defective I/O control
board
• Defective main control
board
1. Pull out and re-insert the image transfer
belt unit.
2. Clean the image transfer belt cleaning
H.P. sensor.
3. Replace the sensor. (Input Check: 5-803-
012)
4. Replace the belt cleaning shift clutch.
(Output Check: SP5-804-036)
5. Replace the drum peripheral component
motor.
6. Replace the I/O control board.
7. Replace the main control board.
[Signal Check]
• H.P.: CN219-B2 or TP108 on the I/O
control board