HP T520 Designjet is able to print black, but chooses not to unless it is an accent or for testing p

[Connor_Snow]

This printer had stopped printing properly around 3 years ago. The problem then and now is that although it can print black, it chooses not. For example, in multiple print tests, it would print black brackets, arrows, and guidelines, but it would not print black smaples. In the pictures attatched, I believe that the brackets in picture 3 are black, the blurry grey/black line in picture 1 and the same lines in picture 2 may be black made from multicolor, and the arrow in picture 4 seems to be grey and not a color combo. However, in each of these, it is shown that there is not a test gradient for black and grey where there should be. The empty bracket in picture three, and the lack of a black to grey gradient in picture 2. So far, in order to try and fix this, I have downloaded the most recent firmware via my computer, as of right now, I am unable to connect to the interent with the machine itself as my school has recently changed the network system and it requires information that I do not have. This brings me to the trickiest part, the printer is at my school and I only have access to it 1 hour Monday through Thursday and 3 hours on Fridays. I have cleaned the printer head both manually, and through the printer to no avail. I am soaking it again as I am writing this, but from my point of view, this seems like a software issue. If any further info is needed please let me know. I will update this as time goes on or until it is solved.

[Valsimot · Accepted solution]

That is defective printhead it doesn't print black. Those brackets on page 3, if you look closer, aren't black, they are browner/greyish because they are printed with a mix of cyan magenta and yellow.

If you have done all cleaning both manually and from the printer then it's time for a new printhead.