Help please

[jigsaw]

Xc540 printing bands after about 1/3 of the way into the print and then not on the leading edge so the first of these three prints is fine, the othe 2 are crap. Happens when printing a solid colour then not on all vinyl, tried static chain, heads are fine so out of idea's

 

[JoshLoring]

Try cleaning your encoder strip

 

[JoshLoring]

I usually clean with ISO and then wipe with a damp microfiber cloth. I do the entire strip, then a normal manual cleaning.
If your running a lot you should do this often. You would be surprised how much "overspray" gets on that strip. I think we clean 2-4 times a week.