Was flying yesterday with my P3S at a local field.  Nothing but grass, no obstacles at all, and flying in P mode.  Got about 120 yards out @ 40 feet up and got the signal lost error. Go reported Lost RC control and video from the bird.  Tried to use RTH on the screen - Failed. Tried RTH on the RC via switches - Failed.  So now I am thinking...hmmm... well I tried the RC controlls and they worked. Using them in ATTI mode I was able to spin it around and bring it back and land it.  

Questions is - if it lost signal, why did it not RTH? Secondly, if the controller was still "actually" working, but not showing on the screen that it was, why did RTH on the RC itself fail to function when I triggered it? If I had not had manual control through the RC I would have had to run under it and wait for the battery to die before it landed under low power.  This would have been fine here, but if this had happened over my camp it would have been GONE.

Just some details - Using Galaxy Note 3, latest version of Go and latest firmware, battery was near full, and the bird is less than two weeks old with approx 2.5 hours of flight time.  

Can't answer everything - but there are at least two radio links to the bird - one is the wifi and one is typical R/C just like any (toy or hobby) bird.
The R/C rarely fails which is why the sticks have always worked - even on my P3P - when the application disconnects.

Some P3S models have had range problems - out-of-the-box. I'm not sure if the fix is software or hardware, but it always pays to try a few things first (reinstall newest FW and Go App, etc) before sending it in.

I'm guessing that you only lost video, but still maintained RC signal. (hence the UAV still responded)
And when you hit the RTH, it allows you 10 seconds to cancel. But since you had no video, you couldn't see it on the screen.   

Capt. Wild Bill Posted at 2016-9-21 23:10
I'm guessing that you only lost video, but still maintained RC signal. (hence the UAV still responde ...

I tried RTH on the screen, and it gave me the option box to cancel - I just let it run out.  After that failed I activated RTH on the RC itself, and that also failed.

Go reported Lost RC control and video from the bird

Did you have video the entire time??

Tried to use RTH on the screen - Failed. Tried RTH on the RC via switches - Failed.

I tried RTH on the screen, and it gave me the option box to cancel

Now I'm really confused..
Which is it??

Capt. Wild Bill Posted at 2016-9-21 23:28
Go reported Lost RC control and video from the bird

Did you have video the entire time??

Sorry I was not explaining it right Bill - When the phone reported lost signal, I lost video as well.  I hit RTH on the phone, and the message popped up giving me a chance to cancel it - I did not cancel it, and got an error saying RTH failed.  

After that I triggered RTH on the RC with the switches - and waited to see if it would come back. It did not.  During the entire time I had no signal to the RC (reported by the Go App) or any video.  Sorry if I confused anything.  

devildog9999 Posted at 2016-9-21 12:54
Sorry I was not explaining it right Bill - When the phone reported lost signal, I lost video as we ...

What is your RTH set at?
Is there a chance that the delay in coming back was your UAV descending/ascending down to the height that you have set in the RTH settings?

Capt. Wild Bill Posted at 2016-9-22 01:33
What is your RTH set at?
Is there a chance that the delay in coming back was your UAV descending/ ...

RTH is set to 150 feet, but the UAV never ascended from 40 from either the Go App or the RC switches. - it just sat there hovering and didn't move until I tried the sticks.

Hi, I have checked your flight record and there is no much useful information.
I'd suggest you to email the DAT file to tech support,they will arrange an analysis for you to find out why the RTH failed.
They can be contacted via support.us@dji.com.
Here is the method to find the DAT files.Hope it helps:
1.Connect your drone to your PC with the USB cable through the Micro USB Port under the Phantom Label in the front.
2.Turn on both your drone and controller, connect your phone to your controller and open DJI pilot
3.This option is under MODE_MC Settings_Advanced Settings_Enter flight data mode.
4.Select that DAT files with the correct date on your PC and send them to tech support

devildog9999 Posted at 2016-9-22 02:48
RTH is set to 150 feet, but the UAV never ascended from 40 from either the Go App or the RC switch ...

Could you please follow Mindy's advice at your earliest convenience?

It may be that the RTH through the App is not the same as that through the R/C....so I would think the R/C switch RTH might work when the app doesn't.

But we have no way of knowing which command is mapped to which system.

same thing happened to me recently. it seemed to happen after i updated though. was working fine the day before when i updated then it started loosing the video signal but had normal control. It like the app and P3P were out of sinc

Most often with the standard,  the video signal is lost first,  but not always.  But,  if the control signal is truly lost,  then there should be a 3 second delay and then rth will activate, and it will rth,  provided the rth point is properly set,  the rth mode is properly set and you are more than 20 meters from the home point.   If you are less than 20 meters,  it will land in place.  If you are below rth set height,  it will increase altitude to that height and then rth.  If you are above rth set height,  it will maintain whatever height is  at and rth,  after a short delay. If it is about to automatically rth due to control signal lost,  and you move the sticks during the 3 second delay time and it receives that command,  it will cancel the rth automatically, because it recognizes the signal is restored.  This can happen with the Standard .  It does happen with the Standard.  If rth begins,  after the 3 second delay for automatic rth due to signal loss,  it will begin to return to home.  As long as the signal is truly lost,  you will not be able to cancel rth or to direct the phantom in any way.  Becausee the signal is lost.  Once you are back in range,  signal reconnected,  then you can cancel rth or just guide the aircraft to avoid obstacles while it continues to rth.  Once it begins signal lost rth,  or any automatic rth mode for that matter,  you will have to manually cancel rth to turn it off.  The only time it will automatically cancel automatic rth is,  as I said,  if it recovers the control signal in the 3 second pause between signal loss and actually beginning to move to rth.  Rth for critical battery is slightly different of course.  All these things are dependent on several variables  like rf interfence from nearby transmitters,  sunspots magnetic fields etc.  Those parameters are fairly constitant and will be known to the experienced operator.  Anything other than those behaviours are 1 of 2 things.  A binary set solution.
A) Operator error
B) broken hardware.
99 percent of the time,  the reason is A.