LaserJet CP4025 - Line on printout

[gruener]

With our HP Color LaserJet CP4025 we have for a long time the problem that on the printouts a line is to be seen. In the beginning it was only easy to see, but meanwhile this line is already extreme. Since we also use the printer for important business prints, the situation is almost unbearable at the moment.

The line is printed exactly at 5cm from the left side.

The image transfer kit and also the image fixer kit have already been exchanged and both are still in order.

On the attached picture you can see that the line is already stronger than the line of the footer on this printout. 

What could cause this line or what can you do to make it disappear?

Update 11.Oct.2018 - 11:40:

I tried the printer "cleaning page" once but unfortunately without success. 

[Copier-Pro · Accepted solution]

Hi I would like to assist to the best of my ability to solve your problem.I hope the information i supply will be of help.

This line could be on the black drum unit of the machine.In this case the black drum will have to be replaced in order to resolve the problem.Hope this helps.

[gruener]

Thanks for the tip. The black toner was about to run out and we had already bought a replacement. We wanted to wait until everything was completely empty, but that was the mistake. Toner changed and now the line is gone. THANKS for the hint.