No menu comes up, SD card out, reset button held in, plugged box in, held for about 90 seconds - nada.
Then I tried what I listed above - freshly formatted SD card, recovery files only. Hold down button, SD card in, plug in power - hold for 20 seconds then let up. Let sit 1 minute (supposed to be 10 seconds with button down, then ~12 seconds for the fix).
Tried again, no SD card, button down, plug in - held for about a minute and still blank screen.
Removed recovery files from SD card, put Firmware 1.1.6 files on SD card, inserted card, held down reset button, plugged in. I was completely shocked after 10 seconds or so when the screen popped on and I saw the droid updating screen! OTA Updater still (again) gives me invalid ROM & device combo! but apparently that is to be expected until the firmware shows up in OTA Updater. The most disappointing part of all is XBMC is still at 12.0 and the myth PVR client is still at 1.6.7 - the XBMC bugs that really kill PVR for me are still there.
At least I\'m back to a fresh install MX2, even if I have to set everything up again and I probably will not even use it until XBMC/PVR client has an upgrade available. Perhaps I\'ll try to find a non Matricom version that supports hardware decoding AND is a more current release. Various bits of XBMC seem to be doing upgrades, so I\'m going to let it run for now and just see if PVR updates will become available.
For anyone else who runs into this, I can\'t really pinpoint what the issue was, maybe just bad luck? What I can say is everything I did to get me back to a working box I documented above. When I got it fixed I didn\'t have anything plugged in other than power, HDMI and the SD card. No ethernet, no USB dongles for mouse/keyboard, nothing. Hopefully this helps someone.