Poor Copy Quality in Canon imageRUNNER 400

Hello,
first, did you install complete Canon original drum unit or just replaced with not genuine low quality drum?
Maybe the problem is in bad quality of drum.
In original drum unit you get whole unit with new drum, blade and charge roller.

Second, you should inspect the developing cylinder, he is magnetic and in some cases something like paper clip or other metal dirt can stuck on it and cause breakage or damage of drum surface.
I recomend you to remove the toner unit, vacume it and check for foreign materials, also rotate the developing cylinder and look for damages or foreign materials.

Hope that something of this will help!

when you reset RAM the by default setting will be chang. try to get setting back.

Hello, firstly I would check the laser station shutter. When the door is closed the laser shutter must be lifted up to realese the cover of laser unit, so that laser could write on drum.

Also try to copy one page and open the door when the paper is in position beneath drum. Then look at drum, if the "picture" is on drum, that means that you have transfer issues.If not on the drum check laser shutter.

Hope that helped.

Hi,
lets try first with technical side!

When was, last time, preventive maintenance service?

You need on regular base:
- clean optics ( beneath copy glass too )
- replace charge corona
- replace transfer corona
- clean/replace paper pick-up, feed and separation rollers.

In most cases the problem will be solved with new transfer corona assy.

something could be blocking the primary chargeing corona wires/roller. i see it a lot on the ir 5000 when the primary corona assmbly cleaning pads get stuck half way through the cleaning cycle.

Hello sir; When you make a copy, lift up the cover check the exposue lamp is on, if not replace it.

Hello sir;As your descript, it seems need to replace drum blade, if they come with whole cartridge then replace whole cartridge.

Did u run a CCD adjust in service mode ??

the image drum needs to be replaced

thanks for rating

the high voltage board of your machine is abnormal,check and clean all corona wires or charging roller if problem not go repair or replace the board