My HP Designjet T120 won't print - HELP

[Elliot]

My HP Designjet T120 wide format plotter won't print. It stopped right in the middle  of printing a blueprint the other day. It won't print from my computer even though it's connected by wifi. But I tried to even print a test page from the command screen on the plotter itself. I tried to print a report of the ink levels in the cartridges. And I tried to print a diagnostic report. It just won't print anything. It will advance and cut the paper roll.  I opened the cartridge door, and the head returns to the door so I could replace cartridges if it needed that. I turned it off and back on. And I unplugged it for a bit and tried again.

I took the cartridges out, and took the printhead out. I cleaned the printhead with a lint free cloth and then put the printhead and cartridges back in. It said there was still a problem and to turn it off and back on. then it said it was aligning the printhead but it is stuck on 0%. Clearly not doing anything. 

I replaced the printhead almost exactly 1 year ago. But I don't print all the time so I don't think i wore it out so quickly. But maybe? 

MY question is do you think I need to replace the printhead again? Is there a way to know for sure? It costs $330 so I don't want to do that unless it works of course. But I just get the plotter working again. (anybody have a source for less $ than amazon for the printhead?)

Edited 6 hours ago by Elliot