Could be handy for anyone else. I possibly disconnected the link cable whilst powering down then place my charge cable in getting absolutely NOTHING !! No charge light, No power on just completely dead. so i tried the only thing i knew which was hold the volume control down + power button. To my relief after around 15 seconds life came back and i just selected " Continue Boot " from the menu and all is well.
Hopefully this may help someone who gets the issue and thinks ( as i did ) it was completely dead. Needless to say i was in total panic mode thinking i had shorted it out and killed it. Phew !!