Please, DJI officials turn your heads to the problem that occurs with hundreds op P4P! The GPS mode turn off during fligt without any reasons. It happens when the drone is at 10 meters or 200 meters high, during maneurves and hovering, high wind speed and calm. This problem does not occurs P4 and mavic flying the same trajectory couple minutes earlier or later.
Latest Firmware, Latest DJI Go4, all calibrations and so on... Many of pilots here wrote about this issue but there is not any officcial guides how to deal with this problem and why it occurs.

The P4P pilots are the future potential buyers of your more advanced and new drones. But if I am at risk to loose 14 hundreds of bucks in 1 second why I will think to buy Inspire2 with x5S on board and smash it in the moment?

Why are they having the same problem with inspire? Can you put up flight log showing this happening.

True..will like to see the log too..

F        00m 02s        0.0 m        1 m        Tip        Home Point Recorded. RTH Altitude:  90m.
G        00m 03s        0.4 m        1 m        Warning        Compass Error
H        00m 04s        0.6 m        2 m        Mode        Mode changed to GPS_Atti
I        00m 11s        23.1 m        4 m        Warning        Compass Error
J        00m 17s        54.8 m        14 m        Warning        Yaw Error
K        00m 18s        61.1 m        18 m        Mode        Mode changed to Atti
L        00m 18s        61.1 m        18 m        Warning        Yaw Error. Warning:Compass Error. Exit P-GPS Mode
M        00m 18s        61.7 m        19 m        Warning        Yaw Error
N        00m 19s        65.4 m        23 m        Warning        Yaw Error. Warning:In Flight,working,IMU,encountersheading exception,please switch to atti mode if craft behave abnormally
O        00m 19s        65.9 m        24 m        Warning        Yaw Error
P        00m 19s        67.3 m        26 m        Warning        Compass Error
Q        00m 21s        70.9 m        39 m        Warning        Yaw Error
R        00m 24s        70.8 m        55 m        Warning        Yaw Error. Warning:Weak GPS signal. Positional accuracy may be compromised. Please fly with caution.
S        00m 24s        70.8 m        56 m        Warning        Yaw Error
T        00m 29s        70.4 m        63 m        Warning        Yaw Error
U        00m 34s        71.3 m        68 m        Warning        Yaw Error
V        00m 36s        72.0 m        78 m        Warning        Compass Error
W        00m 46s        76.7 m        66 m        Mode        Mode changed to GPS_Atti
X        00m 47s        76.8 m        66 m        Warning        Speed Error
This is part of today flight LOG. How can I share more detailed information with you?

skywatch111 Posted at 2017-9-26 09:09
F        00m 02s        0.0 m        1 m        Tip        Home Point Recorded. RTH Altitude:  90m.
G        00m 03s        0.4 m        1 m        Warning        Compass Error
H        00m 04s        0.6 m        2 m        Mode        Mode changed to GPS_Atti

prob try and do a IMU or compass calibration

skywatch111 Posted at 2017-9-26 09:09
F        00m 02s        0.0 m        1 m        Tip        Home Point Recorded. RTH Altitude:  90m.
G        00m 03s        0.4 m        1 m        Warning        Compass Error
H        00m 04s        0.6 m        2 m        Mode        Mode changed to GPS_Atti

That’s not a gps problem that’s a compass problem

skywatch111 Posted at 2017-9-26 09:09
F        00m 02s        0.0 m        1 m        Tip        Home Point Recorded. RTH Altitude:  90m.
G        00m 03s        0.4 m        1 m        Warning        Compass Error
H        00m 04s        0.6 m        2 m        Mode        Mode changed to GPS_Atti

Why would a compass error disable GPS?
Orientation (compass data) and position (GPS data) are different but related.
When the P4Pro is moving and getting position information from the GPS that tells the P4Pro that it is travelling in a different direction from what it's getting from compass data, The P4Pro programming can't work with the data conflict.
The solution is to drop data from one source and since the Phantom can't fly without a compass but can without GPS, it's the GPS data that gets dropped.

I'd be curious about when where or if ,you calibrated it and where you launched from as these may be relevant factors.
It would also help to see flight data , if you could upload to phantomhelp

http://www.phantomhelp.com/LogViewer/Upload/
click link and follow instructions come back here and post your link.

Thank you!
Here is the link
http://www.phantomhelp.com/LogViewer/8WHE5QP038B44FARP5YI/
This errors happens only with P4P. I calibrate my compass regulary and even demagnetize it periodically with CFixerThere is no any issues with Mavic at the same locations. This is my second P4P and the first one had the same problems. I think it is system error in phantom 4 PRO

Bad compass. When the compass goes bad the GPS can no longer get directional data so shuts down. Was a common problem on P3S too.

If compass calibrations don't fix it you could replace the compass - it's pretty easy - involves replacing the legs which contain the compasses and antennas.

It would be worth heading out of the city, away from all that metal, and doing a calibration - and try again

One more flight. The compass was demagnetized before flight and calibrated. IMU was calibrated a day before. Compass error appeared in 900 ft above where is no any piece of metal

http://www.phantomhelp.com/LogViewer/SEJNP7R9NQDDOXB09M0R/

Either your compass calibration is no good, or there is serious magnetic interference where you are taking off or flying.

How did you demagnetize it?

skywatch111 Posted at 2017-9-26 13:44
One more flight. The compass was demagnetized before flight and calibrated. IMU was calibrated a day before. Compass error appeared in 900 ft above where is no any piece of metal

http://www.phantomhelp.com/LogViewer/SEJNP7R9NQDDOXB09M0R/

"The compass was demagnetized before flight"

How do you manage to demagnetise a solid state device ? I've never heard of that being done.

He did mention cfixer. I would bet he's messed his compass up by probably too much tinkering.

Just has a look at CFixer, looks like a pseudo-science marketing scam to me.

skywatch111 Posted at 2017-9-26 13:44
One more flight. The compass was demagnetized before flight and calibrated. IMU was calibrated a day before. Compass error appeared in 900 ft above where is no any piece of metal

http://www.phantomhelp.com/LogViewer/SEJNP7R9NQDDOXB09M0R/

I think it’s pretty accurate to say your problem is your compass. What can you do.

You could go to completely different area environment and test to see if you are having the same problems.
If they still exist you could try calibration in a completely safe environment follow instructions from your manual NO CFIXER , if after doing this you still have same symptoms, you will almost certainly have to return to dji.
Continually calibrating is a not a great idea whether this was the cause of your problems I cannot say for certain and added to that using cfixer to demagnetize is very strange, I have never heard of this before but I think it would be a good idea to scrap this, you have 2 other drones you say they are fine my advice is if these are fine don’t be calibrating them and don’t use CFIXER on them they don’t need anything doing to them.
It’s a pity that still so many advise others to calibrate when there is no need and this can be the most detrimental thing to happen to your drone if done incorrectly.
Again I’m not saying this is what happened because I have no way of knowing for certain, so try what I said and if it’s no better send it to dji, because this looks like an accident waiting to happen.

Let us know how you get on.

Thank you all for advices!  I live in big city and often transport my  drones via subway. After passing metal detecting frames and Moscow tube tunnels all my drone compasses become crazy. But after demagnetizing procedure all drones fly straigt and does not show compass error in mid air except P4P.  I'm flying about  8 years and it is not a big problem for me to land drone in ATTI mode, but compass error may occur when I fly near buildings and trees and I'll crush it certainly. I'm flying 2-3 locations per sunny day and did not noticed any system in compass errors. It can occur when I fly over rye field 500 feet above and do not show any issues when I fly near iron bridge.  The big problem is that this errors happened with my first P4P unit I get rid of this summer. And the second one repeat all its errors. I want to hear any word from DJI representative. I know that they have very detailed service statistics and can hint me what to do next. If I get another Pro can I be sure this errors will not occur in future?

skywatch111 Posted at 2017-9-26 15:50
Thank you all for advices!  I live in big city and often transport my  drones via subway. After passing metal detecting frames and Moscow tube tunnels all my drone compasses become crazy. But after demagnetizing procedure all drones fly straigt and does not show compass error in mid air except P4P.  I'm flying about  8 years and it is not a big problem for me to land drone in ATTI mode, but compass error may occur when I fly near buildings and trees and I'll crush it certainly. I'm flying 2-3 locations per sunny day and did not noticed any system in compass errors. It can occur when I fly over rye field 500 feet above and do not show any issues when I fly near iron bridge.  The big problem is that this errors happened with my first P4P unit I get rid of this summer. And the second one repeat all its errors. I want to hear any word from DJI representative. I know that they have very detailed service statistics and can hint me what to do next. If I get another Pro can I be sure this errors will not occur in future?

Just to verify, is the compass calibration successful? If not, please contact the local dealer and send it in for  fully diagnosis.

Every time I calibrare compass I get "Compas calibratiom successfull" on screen message.

skywatch111 Posted at 2017-9-27 08:17
Every time I calibrare compass I get "Compas calibratiom successfull" on screen message.

You can't "demagnetize" any part of the drone.  What are you physically doing to the drone when you "demagnetize" it?

method007 Posted at 2017-9-27 09:47
You can't "demagnetize" any part of the drone.  What are you physically doing to the drone when you "demagnetize" it?

Hi! There are very few reviews of the device I use in English. Here is one.


Many drone users write that it is pseudo-science scrap, but I noticed that this device is very popular in local drone service shops here in Russia and servicemen does not hurry to advertise it to their clients preferring to use it in their work.