Canon C7010VP - poor quality grainy prints

We're running a c7010vp with a Creo server. Distinct drop in quality on all prints in that all have a serious grainy/sand effect. Especially noticeale on solids but also present in images. Same artwork run through a Konica Minolta C1060 delivers clear smooth images so it's not the artwork at fault.

I have seen many similar posts in the past but none that have been resolved. is there a solution to this?