HP Designjet 130 color streaks on a large photo format size

[emmaachile]

I get this color streaks on a large format print on my designjet 130. It only appears on a size bigger than 16x20. I have changed the cartridges, printhead and have even primed the ink tubes. I have also tested three diffferent photo papers and it still appears. Any ideas from anyone on this?

 

[emmaachile]

I finally solved it by cleaning the thin transparent belt in the printer and i now have a clean sheet. That was a really tough one.