I just bought a Phantom 2 from the classified section on RCGroups. It arrived in a goprofessional case and was packed with upmost care. When I took it out for the first flight it flashed green red red red. I took it home, hooked it up to my computer and swtiched it back into phantom mode and tried again in a different location, this time it was flashing a slow yellow. I know that it wasn't the fast yellow (no TX) because I could still control the gimbal and arm it (with no props). Next thing I tried was opening it up and make sure everything was still connected. Turns out the GPS was unplugged. I plugged it back into the board, took it outside and powered on the phantom. Still no luck, slow flashing yellow lights. Not sure what more I can try. Is the GPS dead?