Problem with Phantom 3: no feedback from copter to RC

[Ulrich]

Hello, colleagues!

I've bought a crashed Phantom 3 Standard and now repair it.

I met a problem and can't find solution yet: there is no feedback from copter to radio controller. Symptoms:

- link LED on copter lights green;
- link LED on RC lights red;
- copter flies, responding all commands from RC mechanics on gimbal works;
- the main board looks unharmed, antennas' cables and other connectors are attached toughly;
- DJI Go app don't see the copter;
- procedure of connecting copter to RC does nothing.

Can anyone suggest where to look for a solution? Is there any electrical scheme of main board?

Sincerely

 

[mpshev]

I would delete the app or all cach files and try that

 

[mpshev]

Of course reload the app

 

[mpshev]

If that doesn't work, take out the SD card while it's off. Turn on quad and put the SD card back in when the quad is on for at least a minute.

 

[mpshev]

What I mean is wait for the quad to be on for at least a minute before you out on the SD card

 

[mpshev]

Put in. Sorry no glasses on [emoji23]

 

[Ulrich]

Which card do you mean - in camera or on the main board?

 

[tevek]

Which card do you mean - in camera or on the main board?

The one in the camera.

 

[Budman]

...

 

[Ulrich]

I think the app is not the reason. It equally doesn't connect from Samsung A7, IPhone 5s and Android simulator on my laptop.

Maybe the reason is TX antenna on copter? Could it be damaged in crash?

 

[Ulrich]

So, I localized the problem a bit.

Something wrong is in circuits between the central board and 2,4 GHz antennas. What I see:

- the grey ribbon cable between the central and gimbal's mother boards is good;
- green led on the mother board lights still;
- red led on the mother board blinks red with long interval.

Tomorrow I'll try to watch signals with oscilloscope and find broken circuits or hardware...