My epson 7880 printer exhibited a few lines missing on a nozzle check, so I went to YouTube to find a solution. It was advised to fold three plies of a paper towel about an inch for each fold. Then, you are to apply window cleaning liquid and bring print head over the folded paper towel. The next step is to work the paper towel back and forth to clean the print heads and print another nozzle check. I repeated this step two more times trying to get 100% of the lines to show up on the nozzle check. Unfortunately, I was not able to get to 100%.
After the third time, the printer stopped printing at all! The next step was to call Epson service, and the tech told me to wait until the next morning to see if the problem cleared. It did not. Again, I called the Epson tech and told him the printer was calling for three inks to be replaced for a power cleaning. Since I did not have a Cyan cartridge, it was impossible for me to do a power cleaning. He gave me instructions for a lighter cleaning, which I did. After two light cleanings of the heads, the printer started working again.
The next morning my first print was horrible. It was washed out and lackluster. The next print was almost in black and white. A nozzle check showed about half of the print heads clogged. A couple of light nozzle cleanings got me back to normal, and the following morning the nozzle check showed very few clogged nozzles, and the colors in my prints were amazing. At this point, I'm hoping I'm back to normal.
So, I wrote this thread to warn everyone about instructions found on YouTube. My suggestion is to use Epson's instructions to the letter and let the helpful techs walk you through problems on their telephone support lines. They have been very friendly and helpful and a great resource for me.