I believe I have one or two of those, but I don't use them. During this
test, is the printer connected to a computer, or are you trying to run
it in a stand-alone mode?

I have a pair of 612C printers that have a weird problem. I found both
in the trash. One, I've had for a while, and I have the driver,
downloaded from HP, on the computer. I attached the more recent one I
found to the computer. It wouldn't work. I attached the original
printer to the computer, and it did work. For a while. Then, after
working flawlessly for several pages, it stopped working too. I changed
cables, to no effect. My guess, and it is only a guess, is the the plug
and play printer identifies itself to the computer not only as a 612C
printer, but as a 612C printer with a specific serial number. I suspect
that, in an effort to thwart pirated software, HP requires that the
printer with a unique serial number originally in use with the software
is the only one that the driver will recognize. If you use the software
with a 612C with a different serial number, it won't work.

Maybe, if you reinstall the software and try printing, this time the
printer will work.

I emphasize that this is only a guess, and that I could be all wrong.
But in an era when ink tanks report to the computer that is time for a
change, whether they still have ink or not, is it really farfetched?