Digital BW, The Print

Hi,

I am writing to gain some insight as to what is going on with both 
of my 1160 printers.  I have been successfully using Lyson SG 
inks in the printers for around a year.  I have been filling after 
market carts with the bulk ink and I use a fresh cart for each ink 
loading.  Recently, after introducing new cartridges, the black 
nozzle check looks very bad with only 25 – 50% of the lines 
showing up.  The lines that do print are not distorted and show 
up in the proper place.  Based on these symptoms, does this 
seem like air entrapment or could it be print head failure?  

I have tried just about everything including letting the printers sit 
for 4-5 days, putting flushing carts in them, putting new refilled 
carts in them, Switching back to Epson inks etc.

Do any of you have any suggestions to get the printers running 
again?

Thanks!

-John Chervinsky