P2V+ very strange and dangerous problem

[zeus2425]

Hello fellow Phantom Pilots.
I bought a used P2V+ that I was assured worked completely fine on a test flight before the seller put up the offer.
However, no matter the flight mode I try, immediately after takeoff it will just shoot off backwards at a slight angle with a high speed.
On the first flight I had a flyaway, rth could also not stabilize it. It tumbled through the air like crazy till it came down.
It would not react to any control input and I couldn't get it to stop climbing.
I gladly got it back with no damage and the following flight test were done on a cord from 4 sides so I could reliably grab it out of the air.
There is no indication to any kind of sensor error or anything strange.
The escs and motors work and with no props on do exactly what they are supposed to do.
I tested the barometer, compass, gyroscope, accelerometer and gps for accuracy and correct reaction on all axes.
I really don't know what could cause this and can't find anything on the internet that would help me...
I hope somebody has an idea what could be wrong.
Kind regards,
Colin

 

[N017RW]

Hello fellow Phantom Pilots.
I bought a used P2V+ that I was assured worked completely fine on a test flight before the seller put up the offer.
However, no matter the flight mode I try, immediately after takeoff it will just shoot off backwards at a slight angle with a high speed.
On the first flight I had a flyaway, rth could also not stabilize it. It tumbled through the air like crazy till it came down.
It would not react to any control input and I couldn't get it to stop climbing.
I gladly got it back with no damage and the following flight test were done on a cord from 4 sides so I could reliably grab it out of the air.
There is no indication to any kind of sensor error or anything strange.
The escs and motors work and with no props on do exactly what they are supposed to do.
I tested the barometer, compass, gyroscope, accelerometer and gps for accuracy and correct reaction on all axes.
I really don't know what could cause this and can't find anything on the internet that would help me...
I hope somebody has an idea what could be wrong.
Kind regards,
Colin

zeus2425,

You said: "There is no indication to any kind of sensor error or anything strange."

Is this while connected to the Assistant?

When connected you can see the IMU and Compass values/data.

Have you calibrated the controller?

 

[zeus2425]

zeus2425,

You said: "There is no indication to any kind of sensor error or anything strange."

Is this while connected to the Assistant?

When connected you can see the IMU and Compass values/data.

Have you calibrated the controller?

Yes, I used the computer assistant tool.
Everything seems fine.
Once in ATTI mode I could hover for 3-5 seconds after takeoff before it went off.

 

[N017RW]

Yes, I used the computer assistant tool.
Everything seems fine.
Once in ATTI mode I could hover for 3-5 seconds after takeoff before it went off.

I can't help any further if all the sensors check nominal with the assistant and the controller has been calibrated stand-alone and with the aircraft.

Good luck, let us know if you resolve (and what fixed it).

 

[David Bruce Kerr]

I think I would try to recalibrate the controller to the aircraft. (Unbind then rebind). If that didn't work then try an advance IMU calibration. Good luck.

 

[N017RW]

Do one thing at a time, then test.

This way you can be certain of the fix.

 

[zeus2425]

Do one thing at a time, then test.

This way you can be certain of the fix.

The problem is that I don't have a point to start at. All systems show correct behavior and everything sits firm and tight.
I already tested everything that I can think of.

 

[AndrewCCM]

Had similar problem.. Turned out to be the Controller Calibration. After calibrating everything in Assistant (Advanced Calibration) twice...I then did all of the controller controls... took it out and it seemed to be a LOT better. Just received the P2V a few days ago and it had a bad motor and esc (not to mention the dead live video wifi board). I replaced the ESC and Motor and took it up and nearly crashed immediately.... It was all over the place. The Assistant 2 advanced calibration along with controller calibration seems to have done the trick. I need to test again just to be sure though. It was a very short test flight...

 

[zeus2425]

Had similar problem.. Turned out to be the Controller Calibration. After calibrating everything in Assistant (Advanced Calibration) twice...I then did all of the controller controls... took it out and it seemed to be a LOT better. Just received the P2V a few days ago and it had a bad motor and esc (not to mention the dead live video wifi board). I replaced the ESC and Motor and took it up and nearly crashed immediately.... It was all over the place. The Assistant 2 advanced calibration along with controller calibration seems to have done the trick. I need to test again just to be sure though. It was a very short test flight...

Ok,
I sadly couldn't get the radio connected to my computer yet because of driver issues and also not feeling the need to check that.
I have, however, done the advanced IMU calibration on solid and firm ground.
A battery I received yesterday is also completely dead

 

[N017RW]

Ok,
I sadly couldn't get the radio connected to my computer yet because of driver issues and also not feeling the need to check that.
I have, however, done the advanced IMU calibration on solid and firm ground.
A battery I received yesterday is also completely dead

I originally mentioned the controller needs to be calibrated itself (stand-alone) then it needs to be calibrated with/to the aircraft.
Not sure why you don't feel the need given the issues you are having. It is possible that there is an offset or other level issue that is present in the control signal causing a bias that the aircraft 'sees' as an input as a result.

 

[zeus2425]

I originally mentioned the controller needs to be calibrated itself (stand-alone) then it needs to be calibrated with/to the aircraft.
Not sure why you don't feel the need given the issues you are having. It is possible that there is an offset or other level issue that is present in the control signal causing a bias that the aircraft 'sees' as an input as a result.

Don't get me wrong I just didn't think of that because the inputs work correctly in the Phantom Assistant and also on the Copter itself.
I will nevertheless do it now that you mentioned it as a possible source of problems.

 

[zeus2425]

Alright small update:
Got help by a friend who flies a Phantom 1.
We couldn't figure out the problem.
Manual mode seems to work in the other modes it will still go full bonkers and only be held back by the rope we tie it to.
We also did the firmware hard reset.

I'm considering to buy a new Flight Controller(MC).
What do you guys think how the chances are of that fixing it?

 

[ARM]

You have to start some where, try the cheapest things first...