Digital BW, The Print

Hi Folks,

I've had a C86 for a few years now and until yesterday it worked fine.
 But suddenly it is now printing horizontal black lines (about 0.35"
apart) on the page.  I've rest the printer and my PC but the problem
is still there.  It doesn't matter what I print, I still get the
lines.  If I print with "Plain paper" the lines are 0.35" apart.  If I
print with "DuraBright Ink Glossy Photo Paper" the lines are much
closer together (about 0.04")

Any ideas?  Or is my printer a goner and it's time to buy another?

Thanks,

Richard Cooke