Recently for no reason, there are yellow lines across my print from my Epson SureColor P600. I cleaned the heads and the problem is still there. I use Epson ink cartridges, not bootlegs.
What is causing this, and how do I fix it?
Source: I am an ex-Epson service tech.
First, this is mostly an educated guess as you havent supplied an example.
The presence of Yellow lines means that there is a LACK of one of the other 7 inks in that area, for example if you are expecting a green area (Grass/trees) and you get yellow, then Cyan/Light Cyan is missing. You can tell which are blocked by printing a test-sheet.
There are various reasons for this, but basically you have blocked nozzles, and the printer needs a proper service as you probably can't clear the problem yourself without wasting a large amount of expensive ink.
If it is in warranty, take the printer to an authorised service centre - they have service inks for just this purpose.
If its out of warranty... time to break out the syringes and cheap inks!