I done it. I carfully removed the unit. Behind, I found 4 large spaces and 8 smaller. I carefully clean them with a dry cloth, I used a pen with a gum to help the cloth to gon on the spaces.
But the result is exactly the same. I don't understand what can be wrong.
Thanks for your help.
When this problem appears, I ordered and changed the Image Unit. So it's a fresh one. I add two prints with cmjn colors. It's the same image with a 180° rotation. You can see the same effect on black and cyan rectangles. Not visible on magenta and yellow. I changed my black cartridge with my backup one, I got the same problem. I tried all appropiate functions on maintenance menu, clear developper, uncharge toner, nothing works. It's a big mistery.
It would be very sad to not use this phaser anymore , it's a good machine
Thanks for reply.
Since a few months, my phaser 6500 prints a ligther stripe on all printings, any color. I changed cartridges a, Image Unit, I cleaned the laser unit, tried to calibrate colors with the menu on printer, nothing changes. Anyone knows what kind of desease my phaser is suffering ?
Thanks a lot for any help.