Epson 7800 covers whole page with black ink

My Epson 7800 worked perfectly a week ago. Today I did a nozzle check and, instead of the usual pattern of fine grids for each ink, it printed out two bands of dark stripes. I turned it off, back on, tried again with the same result. Then I tried printing an image (out of Lightroom); the result was a sheet dripping with black ink, covered from edge to edge except for the leading edge, with just a faint outline of the image under all the black ink.

 

Does anyone have any idea what is going on?

 

The image below is of the nozzle check; no point posting a photo of a solid black page!

 

Not met the problem myself - all I can think of is removing the cartridges, cleaning carefully the electrical contacts both on the cartridge

and in the printer, replacing the cartridges and trying another nozzle check.

 

HTH.

And try a gentle shake of the cartridges then pop em back in the printer and try the nozzle check once again.