Epson 4800 printing error - black line across entire print

[scotton1breath]

Hi,

  I have printed with my Epson 4800 for the past few years and everything has been fine until recently.  The prints still come out looking great as well as the nozzle checks except for a horizontal 1/8" black line that is printed in the center of the image.  I have run nozzle checks as well as power cleanings, updated the firmware and have moved the carriage and cleaned the area where it sits, but I am still getting the same black line on all of my prints.  I have attached an image of one of the nozzle checks as an example.  Any ideas on how I can fix this would be greatly appreciated. 

Thank you,

Daniel

[Sven W]

Never seen before
The 48 is a workhorse, but it is some years ago now, that it was manufactured.
Either the printhead or the mainboard, has freaked out.

/Sven

[Peter McLennan]

This problem is identical to what I've just experienced with my 4800, only my line is magenta.  

Three separate Epson repair facilities (including the Epson Pro tech help line) independently diagnosed it as a head problem.  ie, you need a new one.  If you print a diagnostic page from the front panel (which is plain ASCII) and you still see the line, the head problem is confirmed.

Count on $500 or so, including labour.  The head is about $340