Nice to read of your success, Christian. I didn't read it until after I had found HP Device Manager (I right-clicked the HP icon in the upper right corner and there it was). But when I tried using it, I ended up with this:
noHPdevice.png
Running
hp-setup just looped back to the same, so then I tried
CUPS web interface which turned out to be very familiar, although it went through the process as if it didn't remember ever doing it before.
At one point I was very pleased to see this bit appear: "usb://HP/OfficeJet%20Pro%208710?serial=CN668EW061&interface=1." My Raspberry Pi shows those same numbers as
device URI, so I thought maybe I was successful this time. Then I tried the test print. As usual, out came the Ubuntu printer test page with the eight colored circles half solid half dotted, with the same old errors. Yellow virtually invisible, and two thin red lines across the central white circle inside the shaded gray circle.
Well, presumably that at least meant that there was an HP Device installed, so I went back to HP Device Manager, and got the same "No Installed ..." window. I tried
F6 and
Device | Refresh All. Still, "No ... Devices ..."
I have no idea where to find any "Generic" anything. The only list I usually get has only
HP_OfficeJet_Pro_8710 and [ditto]
_Fax on it.
I've always been able to print well from the Amiga side, but the print program I use there can't do two-sided printing. I guess I'll give up and go back to printing through the Raspberry Pi, which does everything right.