Today, something weird is happening: when I try to print (from TextEdit) from my iMac (2017, Retina 4k, running Mojave, printing to a network-connected HP 3055), it ACTS like the document printed, but nothing comes out. I tried cycling power on the printer; no joy. I tried rebooting; no joy. I tried removing and reinstalling the printer; No joy. I tried printing from other applications (Preview, OpenOffice); no joy. From the "HP LaserJet 3055..." application, I CAN'T print a test page, but I CAN reach the printer's web interface, and print a PCL font list from it.
When I copy the document that started this whole mess over to my old Mini (running Mountain Lion, I think), it prints FINE from there. But still no joy printing from my Mini.