Unfortunately, you've told us none of the specifics here.
Operating system used? Make and model of computer and printers? Age of both? What are you trying to print each time? Tried printing something else? If you choose to print a document in red, (for example, create a short document, highlight the text and make it red, then print), does it do it correctly? Have you checked the printer settings to make sure it's not set incorrectly? What EXACTLY happens when you attempt to print in black?
I've not seen a computer that wouldn't print black. It's normally a printer ink issue.
Hope this helps and let us know more.
I am having trouble printing in black. This is the second printer within a month that has had the same issue. Ink supplies are all okay and I've run "clean printhead" options and everything of the sort. Is it possible that my computer be causing this issue and not my printer? It seems ridiculous that two printers would have the same issue given that they're different models and don't even use the same ink cartridges. Any help is definitely appreciated! Thank you.