Epson Aculaser C1600 - clear vertical lines in print

[Ville Hiivola]

I've had this problem before in the past, but then i was able to fix it by cleaning the print head window.
This time, cleaning the print head window did help some, i had two clear lines in the print and other went away after cleaning. The other, stronger line remains..
I don't know where the problem could be, since epson technical support for this printer says clear vertical lines can be solved by cleaning print head window or replacing the print cartridge(s). Now i don't believe the problem lies in the cartridges since the line is in all of the test pages (yellow, magenta, cyan, black), all cartridges cannot have the same defect in the same place?
Epson support page says photoconductor or fuser issues would be displayed as horizontal lines and not vertical?
Thanks for help in advance..

Ville

 

[Ville Hiivola]

The line appears to have black edges, as seen on the coloured test pages, on black/white prints i can only see a clear line..

 

[Ville Hiivola]

Ok, looks like i solved the problem before anyone answered.
I got to suspecting the black cartridge, since the line had black edges with every colour.. So i pulled out the black cartridge again to check more thoroughly. So what do you know it had a visible line on the roller (with no black toner), right where it was on the prints, perhaps dirt etc got there..? So i just cleaned the roller and rotated a couple of times/cleaned again and then shook the cartridge a couple of times horizontally. Then i put it back in the printer. Voila, prints perfectly again!