durst on back print Frontier 570

[komodo]

hi,

i have a durst on my back prints. i have clean all the racks, change PSR but nothing still same prob

any Idea

 

[Magenta]

is this dirt on the leading edge, looks like dirty PSR getting into leading edge and staining. It could be that the leading edge is getting damaged, does it feel fatter, thicker than the trailing edge. The paper fibres are splitting then the PS is seeping in. Back flush the PSR so at least the PSR is clean check all X overs and rack entry guides for rough surface and clean