HomePod flashing + - and won't reset, just returns to flashing +-

Hi folks

ok so I got all the way through resetting my home pod to the red spinning light ... then it started flashing + - again .... back to where I started (deleted from home app, deleted from iCloud already, but same effect)

Running out of ideas and seriously considering a lump hammer as the only option left to reset .... unless you know better! Help please!