Thanks for the reply. Left on charge for a few hours. Tried different ports and a different cable. Tried doing the reset thing. If I hold down the power button for a few seconds, it does show the black screen, but then does not progress any further. If i just press the power button normally it starts up fine. Another thing is when I put a blank formated SD card into the unit, it does not write the ttgo.bif file to it. If I put the card in with the new map on it, the map is listed so it obviously must be recognising the card is there. However without the ttgo.bif file I can't get fast activate to work