P8 p7 p21 in c 250

[kesserling]

I have 3 code p7 p8 and p21 with a c250
i change the 4 image unit and the transfert belt and after the code is the same
i clean the two sensors near the fuser
i clean the sensor near the motor behind the copyer
and the same code
i change the ic (for the consummable )who is in the card on the left of the copyer
anyone have an idea
thanks

[Albonline]

stop the unit while its doing color registration. pull the xfer belt, is there arrows on the front and rear edges of the belt? do the halftone output for each color, how do they look? output the 4 color lattice pattern, are the colors landing on top of each other?

[kesserling]

I just forget to tell you somethings
when i am in the tecnic mode i do reset and stabiliser and after i go see the gradation adjust and the first in three gradation adjust don't go to 0 but the second and the last go to 0
after a moment i redo sabiliser and i take furiously the wire of power and the same things gradation adjust the first don't go to 0
thanks

[kesserling]

I forget to talk somethings
gradation adjust don't want go to 000 while i do reset and stabiliser while in take off the wire power never go to 0

[DCPS]

Check the ribbon cable on the MFPB (from the laser units), pull it out and clean it with contact spray, then try again. Did you try a test pattern? Do you have all colors on the test page? If you have P errors you are not able to do the gradation. You have to eliminate them firstly.

[kesserling]

Thanks
i change the ribbon wire and it remains p8 p21

[abilashvk]

Friend,
We faced this problem and the reason was corroded holder (part no. 4038 2274 01) of the respective IU's.As the machine shows P codes you will not be able to do gradation properly.Only thing is replacing a holder is difficult and time consuming.It is located behind HV transformer PWB and other end behind IU which you can see by just removing IU. first try antirust.treat it as an arching problem.Also, what about the customer location? Is it a humid place?then you can suspect more. there are other reasons offcourse, but your discription seems fit more in this.

[kesserling]

thanks
i try to change it and i will give you the result

[abilashvk]

Friend ,
Before going straight for a holder changing you can check PWB-MFP in another working machine also, as you can pin point the cause.some time MFP board (on Upper Left rear side of the copier) which also have a Parameter chip on it can also do strange things.try individually& both in a second machine.you can try this even in a C252 but not vice-versa. Sorry to tell U this latter as INDIA being a tropical country,we have lot humidity related complaints,which may not be there.

[kesserling]

dear friends

i have change the holder and the springs and now i don't have no code all is ok now tahnks for this remarque

bye