KM C652, the whole page black after drum & blade replacement

[rajabi1367]

I have changed the drum and the blade for Black Unit recently and after that the whole page is printed in solid black, no margins (exactly the whole page), it doesn't matter which color test page or demo page is printed. The patterns of demo page can be seen under the black pattern.
I tested another Drum Unit (Black) and there was no problem so the Developing Unit is ok.
So is there a problem with drum or blade or something else?

[alabovic]

Re: KM C652, the whole page black after drum & blade replacement

Check charging corona, maybe wire in corona is broken.