Digital BW, The Print

I found that my CIS lasted about a year and a half before the black channel 
quit.  I had poor black channel performance and tried many ways to clear 
the "clog", including injecting the head directly with Windex.   When I got 
a good test pattern, I ran a black-only test image at high speed and 
watched as the ink lay-down quickly went from total black to just a few 
black lines on the page.  I deduced from this that it was the CIS that was 
starving the black head for ink, not a clogged head. I bought a new CIS, 
installed it and I'm printing normally again.  Others have commented that 
the black channel (not the head) suffers from clogging due to evaporation 
of the solvent through the Nalgene tubing.


regards,

Peter