Epson 645 cyan print issue

[SandraK]

I recently acquired and Epson 645 workforce. It works great, except the blue refuses to print. The cartridge is not empty (about halfway according to a check). I have cleaned the head and nozzle multiple times with rubbing alcohol unsuccessfully. If I could, I'd take that piece out of the printer and check the underside, buuuut I can't reach the printer. Yellow, magenta, and black work fine. It just acts like cyan doesn't exist.
I'd be grateful for any additional tips.

 

[hang-the-9]

You pretty much checked everything you could without replacing the print head. Which would be the next step to try. Trying a new cartridge may also work.