can anyone tell me why my phantom 2 wih zenmuse h4-3d gimbale takes a nosedive after about 10 min of flight all cali are done and i always do all flight preps before taking off this has happened a couple of times now its only a month old any advice would help

First I would hook up to the assistant and see if I was getting any errors. And check the condition of the battery. If all look good then it's going to be IMU calibration on a completely level surface. RC calibration the before test flight compass calibration. One you know for sure the battery is ok. All calibrations are done and good results then change the props. Time to hand check the motors. See if they all turn freely and feal like they have the same resistance. If ok the start your motors and see if they all start at the same time. Then stop them. Did they all start and stop at same time.If ok then time to start up and  hover  four or five ft over the grass. See if she gets all flashing green rear Led's so you have satellite lock and home lock before take off.  If all is good so far take off and see if she steady and not drifting over a foot in any direction, if low wind. Look at OSD and see if you are looking good with satellites, battery and  telementry data. If all look good and she iis acting right do some short flights out back then left and right checking all control and stick movement. keep an eye on the battery and you flight time. This is all testing your components. If she is still looking good take her up to 25 ft and back down to 6 ft. All go well then go to 50 ft. Hover and if all still is doing good make a circle. Come back down and land. You should have flown about 5-6 minutes now. Shut off the motors and feal them. Are any exceptionally HOT. See if the motors spin freely by hand feal around the shell by the motors to see if any of the ESC feal like they have heated up and have gotten the shell warm. If not and all still look go fly a little more and maneuver around testing. Never to high and never to far. Test the H/L and see if she responds. Back to GPS the go out a little and rest Failsafe. Still good take back control land and check the motors again. None hot and all working good. Finish out the battery till 20-30% land. Wait, cool her off, and charge up for a longer and higher flight. Still testing control and Keeping an eye on OSD for any issues. t any time during the previous test she acts up or doesn't do as expected make a note of what you were doing what the Phantom did or didn't do and  bring the results back to the forum so you can see if a diagnosis can be done to correct the issue. It's all a matter of finding out what it is not.... So we will know what it is. Process of elimination. Good flying and good testing. Get those calibrations right first!

Ditto to the above. It's quite possible the location you were flying in with all the trees  you were flying around caused you to lose GPS lock. Your SATs are not all located directly above. They are all over the sky and in order to maintain a good lock you should fly in clear open spaces. Sorry to see that happen, hope everything is ok with the Phantom.

Seems like some sort of error you cannot do anything about. If the quad was flying okay the first few minutes of your flight, it should not be a calibration error. Offcourse something can go defective in flight. It should not be your GPS signal. When GPS fails, the phantom should switch to atti mode (yellow lights go on), and then its up to you to maintain hight and direction. But seen how the quad went in your movie, i suspect some sort of error in the flight computer, or one of your engines may have failed. But again, this is very hard to tell from the movie. Like Roy said above, you can test everything again, and hope it wont happen again. Unfortionatly there are a lot of unexplainable things these phantoms do sometimes. I have read about it a lot, and unfortionatly it occured to me to, which resulted in a crash.

don77 Posted at 2015-6-28 06:35
https://www.youtube.com/watch?v=On1KUe1CLN8&feature=youtu.be

this is the one from before same nose dive

does anyone think the h4-3d gimbal could do this i bought it off ebay it was in a crash and bent i straitened it 2 of the arms

power system failure or bad battery

Help me with this problem please?

https://www.youtube.com/watch?v=Rd4UnZgw7aI&feature=youtu.be