I have attached the nozzle check you emailed us:
This auto nozzle check shows your LM position was missing at first, and possibly had dirty nozzles and/or back suction, as the first pattern printed four nozzles of a blue/gray color (probably waste ink). The auto nozzle check works by printing a blocky pattern from the first four positions, then the printer reads the printed pattern. If it detects any clogged nozzles (missing blocks), it will do a cleaning cycle and reprint those four positions again. If it doesn't detect clogged nozzles, it prints the second set of four colors, and reads the printout. If it detects clogs in any of the patterns in the second set of colors, it will do an auto cleaning cycle, then start by printing the first four again, then read to check for missing nozzles again before moving on. This is why your printout shows a good set of four colors, then the second set missing LM, then a good set of the first four again, etc... until LM comes back at the end.
I never print the auto nozzle check, and prefer the manual nozzle check, which shows all channels at once. We have a helpful article about auto vs. manual nozzle checks, here: http://www.inkjetmall.com/tech/content.php?167-Evaluate-a-Manual-Nozzle-Check-to-Determine-the-Health-of-Your-Printer
I hope this clarifies what you're seeing.
Best regards~ Dana