Digital BW, The Print

You might want to try this:

This happened to me, and it was a I thought it was a faulty cartridge 
that didn't hold a vacuum, as I have
had faulty cartridges before.  However before you give
up, tape the bottom of the black cartridge, and hold your thumb (or 
preferably someone elses thumb) tightly
over the hole, and draw a vacuum again.  I did this, and believe it or 
not, I didn't get any air or ink in the tube.
When the vacuum has been drawn, clamp it just as you did the first time, 
and then, with the ink tube in the bottle
and the cap screwed tight, release the clamp.  You should get ink in the 
tube.  If this does not work, you may
have a faulty cartridge.  Sometimes, it can take over night for air to 
clear the tubes also.

Jerry