I updated both P4P AC to the latest firmware and my iPad Pro with the latest DJI Go 4 app. All worked fine, and my P4 also worked well under with the new DJI go 4 app.  I then decided to update the P4 firmware to V02.00.0700,, that is when things went south.

After updating the P4 to V02.00.0700 the RC status light strobes red/green, and needless to say, the video on the screen is messed up and none existent.  The HD signal strength shows no bars, and flickers to five bars, then, back to none.  The AC signal is five bars, and I can control the P4 AC just fine.

I have tried everything, including: Reinstall Assistant 2; refreshed the firmware; downgraded the firmware version; reinstalled DJI Go 4;  did a factory reset; reinstalled V02.00.0700; turned off my anti-virus while updating; reset my iPad; other things; and swore a bit too. Still have the issue.

The P4P still works fine, so I suspect it is not the DJI go app.  With the P4, the RC status light remains steady until I turn on the AC, and then it will strobe.  Worked well this morning, however, after the  V02.00.0700 update, no video !

Been at this for a few hours.  Anyone have any ideas?

IS it the latest DJI assistant 2? or did you reinstall the one you already had?

The flashing red/green indicates to me that the RC firmware needs updating, although it's not obvious it is needed to allow RC to communicate properly with aircraft.

Try the following :-

With RC and display connected (aircraft off), and display has a good wifi connection to internet. Run DJI Go 4 (V4.1.20 and above) and 'enter device'. Open the 'aircraft status' screen by tapping the screen at top edge where it says 'disconnected'. The top line 'Overall Status' should show if update required (this may take a minute or two to appear). When it does then tap on that and it should take you through the process to update RC. That may make the difference to your display.

Aardvark Posted at 2018-5-1 00:25
The flashing red/green indicates to me that the RC firmware needs updating, although it's not obvious it is needed to allow RC to communicate properly with aircraft.

Try the following :-

Seems to have resolved the issue.  Thanks Aardvark.

I was going to update the RC, but kept thinking the issue was on the AC side.  What have I learned? "Update All Firmware!"

Thanks again.

Bashy Posted at 2018-4-30 21:05
IS it the latest DJI assistant 2? or did you reinstall the one you already had?

I had downloaded the latest from DJI after removing the older one.  At some point yesterday, I did strongly suspect Assistant 2 was the issue.  However, the issue is now resolved.  Thanks for your input Bashy.

JW5255 Posted at 2018-5-1 02:19
Seems to have resolved the issue.  Thanks Aardvark.

I was going to update the RC, but kept thinking the issue was on the AC side.  What have I learned? "Update All Firmware!"

The firmware from Version 02.00.0106 released last July was dependant on the RC firmware being updated to V1.9.2 (As it was last July).

So if your aircraft had come from a release before that, then any P4 update done also needs RC updated.

The P4 Release Notes for all the builds can be downloaded from link.

Thanks for keeping us updated and I'm happy to see the issue has been figured out. Feel free to contact us if there is any further question.