You can use hp-toolbox with HP printers. Typing it in a terminal will open a GUI frontend to make changes. You can also access CUPS this way.

To check queue from a terminal just type: lpq
You will see job numbers and you can cancel the problem job: lprm 100 (assuming the problem job is 100)
Try printing again.

1 members found this post helpful.

I had no luck with running lpstat and lprm. Perhaps because I might have to substitute something for "printername" - like HP-LJ1020?

When I followed Frank Bell's suggestion about cups, this is the response I got:

1078 ? 00:00:00 cups-browsed
4533 ? 00:00:00 cupsd


As for trying the printer with another computer - I used the printer USB cable and connected it to this other computer. And it worked - i.e. I was able to print the page that I had been unable to print with my new, reluctant, computer. I hope that sequence means something to someone. As for me, I'm just happy that it's working - for now!