OK, enough is enough. Hooked the Photosmart to two other boxes, same naughty behavior. Repairs? Forget it, costs more than the printer did. New power hickey? Forget it, about half the cost of the printer (if I remember correctly the thing only cost $60).
Printer is now designated as scrap and is awaiting county-wide electronics recycle next month.
So's the Business Inkjet 2280tn (dang). Probably a bad Ethernet card, maybe, just maybe, hang on to it (it has PostScript installed) and try another interface or see if I can find an Ethernet card somewhere on line. It really is a nice production printer (for my needs anyway).
Off to Staples, HP Officejet Pro 8600 N911a on sale ($50 off).
Ethernet, USB, wireless (at no extra charge), big ink cartridges (magenta, cyan, yellow, black), automagic duplex hickey for two-sided printing, paper tray, scanner, copier, FAX. Wow, zowie.
Hook up the Ethernet cable, run hp-setup, fiddle, twiddle, viola! Squiggles on paper (both sides even). Wow, zowie.
Never will use the wireless, probably won't use the USB (till I find out that xsane won't work or some dang thing).
Nice printer, hope it lasts as long as the Business Inkjet 2280tn.
All is well that ends.