Digital BW, The Print

One of my 3000s has developed a black striping problem. This 
may have been discussed in the past but I did a search and 
found nothing.

I'm getting an unevenly spaced, intermittent dark black line that 
starts within the image and extends into and beyond the left 
border. It's being printed slightly in front of the actual printing 
area. The output will be fine for an inch or so and then the 
intermittent black line will kick in anywhere from a single line to 
an inch or so and then disappear.

Other than the black striping the output is fine as are the nozzle 
checks, head alignment, etc. I thought maybe it was a dirty head 
so I did an under the head cleaning/blotted the ink pads several 
times but it looks as if the lines are sharply defined, linear nozzle 
bursts vs. smears.

I'm running Piezo/MIS FS with EAM and PRS and the tension 
lever in the + position. It's been fine up until now. 

Could this be the beginng of the end for the print head?

Any ideas?

By the way - does anyone know what the black lever on the right 
hand side of the print head is?

Thanks,

Rick Murai