Digital BW, The Print

When last we discussed the C86 tiny random black dots issue, I had noted:

1) They appear on the paper outside the image area, wherever the head 
flies over the paper;

2) They are reduced by using high speed mode, apparently because the 
number of marginal overflies is lower.

3) It apparently isn't a driver issue, as I have the symptom with driver 
v. 5.5 and 5.4; meanwhile, we know for certain that other C86 users do 
not have the symptom with 5.4.

I can now report that switching my C86 out to the Epson OEM color inks 
and printing some images reveals no errant dots visible anywhere in the 
print.

I can also report that when printing a black square with a white center 
on the paper, the errant dots appear with a random distribution wherever 
the print head passed over the paper; that is to say, the dots appear in 
the margin and inside the square at about the same density. It is not a 
repeatable pattern of errant dots. It is, however, about the same number 
of errant dots per square inch everywhere, and in each print.

When I refer to "tiny random black dot," I'm referring to something that 
is roughly circular, maybe elongated a little in the direction of the 
head travel, and is less than half a millimeter or so in diameter (I 
don't have  a magnified reticle to actually measure it, so this is a 
guess). It is, in other words, small and not obtrusive on a casual 
glance at the image, but quite a bit larger than the dots that appear in 
dark image areas.

Ok, so I'm no expert. What is going on here? The best hypothesis that I 
can come up with is that the EZ black cart is somehow causing ink to 
leak through the head and drip onto the paper, but I would think I would 
be getting much bigger blobs and smears than what I'm seeing if that 
were the case. Any ideas?

-- 
Jeff Medkeff
Eagle River, Alaska