Code c202 bz c451

First check the Laser window cleanliness,
Then check the IU-Cyan and its charging grid cleanliness.

also try in service mode-Image Processing Adjustment-
Background voltage value can be increased.

Check the Transfer Belt assy,
Remove and Clean properly
Remove all Imaging Unit and shake properly and put it again.
P6/7/8/9 indicating all Imaging units are not in good condition.

So at warmup, color patch not getting properly generated

Black or color or both? Check the transfer roller sponge looking roller on the right side cover that opens

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/normanj_7893313f0751935f

what color is the stain? mite need a need a new transfer belt or fusing unit

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/normanj_7893313f0751935f

Black image unit and or drum


try this site Precision Roller Printer Toner Cartridges Parts and Supplies Office...

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/normanj_7893313f0751935f

Hi
The bizhub C451 is a Konica-Minolta machine and I have found a webpage here:
Error Codes Konica Minolta bizhub C451
that details the error codes that can occur on your machine. I know that this may not be of much use as you don't appear to have any error codes appearing. However, there is also a link at the top of the page from which you can get a copy of the Service Manual which will probably have a lot more detail in it and may answer your question.
Hope this is helpful, if so would you please register that with Fixya
Cheers

Back of C451 beside PRCB.

C0105 Tray 3/4 feeder transportation
motor turning at
abnormal timing
The lock signal remains LOW for a predetermined
continuous period of time while the
motor remains stationary.
1) Check the M25 connector for proper connection
and correct as necessary.
2) Check the connector of M25 for proper
drive coupling and correct as necessary.
3) M25 operation check
4) Change M25
5) Change PFTDB
6) Change PRCB

C3461 New Fusing Unit resetting failure
• A new installation is not detected when a new Fusing Unit is installed.

C6103 - Scanner overrun failure
The Scanner Home Sensor detects the Scanner at its home position during a period of time that begins with the time when a prescan command
and a scan preparation command are executed and ends when a home return command is executed.