image drum for c250

[robizhub]

I have 15 image unit (old-used) for C250. If someone new some tricks to use them again:
rebuid kit ? or ...
image drum
Thanks

[Luther]

You can have the chips reset and get more life out of them, havent found anyone that has rebuild kits for them

[robizhub]

I dont understand...

because the machine is working with message: the image unit magenta ... (bla bla ) replace soon.
The problem is when the drum is drawin a red (or black...) line on the paper.
Then the question is the folowing: why should reset the chip on the image unit if the machine is still working?