My HP 6830 stopped printing black.
I went through all of the recommended steps here (including cleaning heads thrice and realigning heads) to no avail.
Later, I repeated the process and it printed black about three times before the problem returned.
I tried the same steps again to no avail.
I replaced the (almost full) HP cartridge with a brand new HP cartridge and tried the steps a third time to no avail.
I reviewed all of the related threads here and tried the unplugging/re-plugging solution that worked for others to no avail.
The warranty has expired and it would be difficult to get this to a service centre in this COVID-19 environment.
Can anyone suggest a fix for this before I end up junking this printer and ordering a really cheap replacement (that will probably cost me less than the HP cartridges I just bought?)