print head fixed the issue on our Design Jet T520 which wasn't even able to come online because of the print head issues. We weren't sure but thought the ink had harddened inside the old print head. The replacement came as directed (couple days) and the swap out was pretty seamless. Simple instructions and we were back up and running in no time.
Easy to change out the existing Printhead with the new one. I had to read the instructions a couple of times before starting to change it out. But once I started to replace it, it was very easy.