OfficeJet T45 all-in-one misbehaving

Running stand-alone (not connected to computer): after
initializing @ power-up, displays "Open cover. Clear
pen carriage jam, then press enter." There is no jam
(at least none I can find). The carriage can and does
move under printer control. Pressing enter doesn't
help, error just repeats.

The print head DOES NOT move back to right-side parking
place upon power-down.

Resetting by holding down '*'+'8' while plugging in power
gives message "NVM ResetPartial PD-409-R T45 o" which remains
until I press power button and get initialize as above.

All other controls just give three-beep complaint.
Power supply is good - borrowed from another (working)
printer.

Anybody know any magic?