That's a strange one mate
you seem to have tried everything that should get it working, normally I would suggest unplugging it to give it a cold reboot but that seems to have been the cause of your problem, was the receiver turned off before you unplugged it
have you got an old Image backup of when it was working ok before you pulled the plug that might be worth a try just a thought, apart from that I am stumped
Try refitting the Hard Drive and loading in an old Image back up if you have one and try a restore
it's been a few month since i sold my Miracle box premium twin but I seem to remember something similar happening to mine but a fresh flash fixed it
SORRY About the Double post I was trying to edit it and got dragged away from the PC