Last week I flew 2 batteries with no problems. But 3rd battery. I took off and display said something like "land now". Display also said upgrade required. I took it home and tried to fly and it worked for a while. Then I lost connection. Screen locked up and I was able to land just by viewing the aircraft. Ok after all that I tried to upgrade the A/C firmware, followed directions. After inserting SD a Card writhe the .bin file on it nothing happens. No sound like it always did. Cannot get RC and Aircraft to connect (ready to fly). I think I have tried everything. I even tried going back to 1.8. Any held will be appreciated.