Digital BW, The Print

Hello all.

I have recently purchased MIS UT-ink (6 colors with Eboni black) for my Epson Stylus Pro 
7500. I bought it un 1 pint bottles since I have refillable cartridges as those found on 
inkvillage.com:
http://www.inkvillage.com/Refillable_Cartridges_Shop.htm

When I bought the printer it was loaded with NanoChrome ink. It worked at the sellers 
house, but after 1800 km in a car ( it might have been subzero temperatures) the blavk ink 
just wont reach the paper. I have drained it for ink several times, washed it and done init 
fills several times. It is not even black ink in the tubes going from the cartridges to the 
head.

I wondered if the problem could be that the Eboni black ink was  thicker than the 
NanoChrome black, but then I remembered that the Nanonchrome black did not print 
either. In the cartridge there is a small "channel" at the bottom were the ink flows before 
leaving the cartridge. Just before the outlet of the cartridge the ink must climb an inch. It 
looks like the black ink never even manage this "climb". The black ink does not seem to 
leave the cartridge at all!

I know it is impossible to ask what is wrong, but can anyone lead me in the right direction?

Best regards,
Eirik Berger
Norway