I had the stuck 'boot' issue, after disconnecting my USB HD. The standard fix of powering off and on did not rectify this. Each time, 20 seconds after pressing the 'standby' button, the display would show '1080p' for 5 seconds, then return to 'boot' and stay indefinitely. Neither ATSC tuner would work in this state. Unplugging for an hour was no different.
My fix was to use menus and execute a 'Reset All', which required a re-scan and re-entry of all upcoming recordings.