I cannot figure how to get the C720 into recovery mode. I have tried the ESC-REFRESH-Power button sequence and it just seems to reboot normally. In my case I am trying to enable the development mode which seems to only be possible when the recovery mode screen is present. Is there some trick to getting into recovery mode? It seems so simple according to what I have read but it does not seem to work. I have tried all types of timing on button presses and the keys definitely work. I tried inserting a USB thumb drive with a recovery image on it with no change. Not sure what else to try at this point.