Digital BW, The Print

I had a 1280 on my shelf as a backup and pulled it down today to use 
it.  I'm guessing that I fouled up the initial print head charge 
because I'm getting no ink at all through the thing and suspect 
there's substantial air in the way. 

Anyone recall if there's a way to reinitiate the print head charge 
sequence?  Other suggestions?  Normally I would troll through the 
archives but rather defeated at this point and appreciate the 
community help.

Thanks,
Cleavis