Which P4 firmware are you running? I and several others on the DJI Forum had issues with newer firmware when HDMI module installed so I've been on firmware version 1.6.0 on remote and firmware version 1.1.301 (7-April-2016) on aircraft for over 6months without any issues.

I've heard heard version 1.1.301 caused issues with signal strength because of the overhead of upgraded encryption of RF signal but hasn't been an issue for me as I try to keep aircraft within RF range at higher altitude and plan flights with little to no obstructions.

PS anyone have the link to PDF list of Controller firmware updates and DJI GO list?

P4 Firmware List to date. https://dl.djicdn.com/downloads/phantom_4/release+note+update+20161107/Phantom_4_Release_Notes_en_20161108.pdf

Which type of problems with HDMI Module? Because I assume to make an R.M.A. of my HDMI Module just bought to Amazon. In effect I have a complete lost of video signal  also with HDMI cable insert also with only the usb cable insert.

I'm talking about video artifacts in your case it may be the video device you're connecting to I would try another monitor.

Davejmedia Posted at 2016-12-30 12:48
I'm talking about video artifacts in your case it may be the video device you're connecting to I would try another monitor.

I have video artifacts too, because the signal is very poor at few metres from radio to Phantom 4.
The signal is very poor even only USB cable is connect. When I Mount the original module without HDMI the signal return very stable without interferences.
In your opinion is a software issue or the HDMI module defective?

Testman, read this thread: we need more people to test and confirm the issue is with Remote Control firmware 1.7, or 1.8 and above with HDMI module installed. If you remove the HDMI module and install the stock module with RC 1.7 or 1.8 version or above do you still have artifacts? Reinstall HDMI module and try to downgrade to RC 1.6 and I'm almost certain the hardware works and it's a firmware issue.

http://forum.dji.com/thread-67226-1-1.html?&page=3

Davejmedia Posted at 2016-12-30 13:23
Testman, read this thread: we need more people to test and confirm the issue is with Remote Control firmware 1.7, or 1.8 and above with HDMI module installed. If you remove the HDMI module and install the stock module with RC 1.7 or 1.8 version or above do you still have artifacts? Reinstall HDMI module and try to downgrade to RC 1.6 and I'm almost certain the hardware works and it's a firmware issue.

http://forum.dji.com/thread-67226-1-1.html?&page=3

5#


I have the latest firmware of november 2016 in my Phantom 4 e the 1.8 firmware in my radio. The issues remain with HDMI module (also I connect only USB cable to my smartphone) and the situation return normally if I replace the HDMI module with the stock module.
I do not able to downgrade to rc 1.6 and to 1.1.301 Phantom 4 firmware. Do you explain me in which mode make the downgrade and how to find those version of firmware?
Thank

Check out this link for downgrade instructions, videos and options.

http://forum.dji.com/thread-48287-1-1.html

Davejmedia Posted at 2016-12-30 14:18
Check out this link for downgrade instructions, videos and options.

http://forum.dji.com/thread-48287-1-1.html

Thank, I was able to downgrade at 1.6 version of Radio firmware, but the video signal lost remain. So I think is the HDMI module defective. I try again when Amazon send to me a new HDMI Module and I post the results.
Goodnight

Testman Posted at 2016-12-30 15:10
Thank, I was able to downgrade at 1.6 version of Radio firmware, but the video signal lost remain. So I think is the HDMI module defective. I try again when Amazon send to me a new HDMI Module and I post the results.
Goodnight

Great Davejmedia!
You are right, is a software problem introduced by the 1.8 Radio firmware with a HDMI module inside.
I have resolved mounting the hdmi module with the 1.8 firmware and downgrade a 1.6 version with the module inside.
My previous error was downgrade with the original module inside and only after mount the HDMI module. In this case the situation remain wrong and the bad quality of video persist, even the very poor video signal even with very high interferences.
Thank you for support

I have the same issues with my hdmi module, it was replaced by the vendor but if anything it's slightly worse. So it seems to be a firmware issue. Oddly the hdmi monitor shows almost perfect video even out to 1200 meters. However, I had  a flight yesterday with pretty good video on the Samsung tablet out to 600meters but started getting breakup when close in. If I remove just the hdmi backplate the issue seems to go away. That is only the plastic cover with the hdmi socket. BTW I'm pretty new to forum life so be kind and offer advice if I'm not doing it right. I'm going to downgrade from 1.8 as suggested.

FCPP Posted at 2016-12-31 22:03
I have the same issues with my hdmi module, it was replaced by the vendor but if anything it's slightly worse. So it seems to be a firmware issue. Oddly the hdmi monitor shows almost perfect video even out to 1200 meters. However, I had  a flight yesterday with pretty good video on the Samsung tablet out to 600meters but started getting breakup when close in. If I remove just the hdmi backplate the issue seems to go away. That is only the plastic cover with the hdmi socket. BTW I'm pretty new to forum life so be kind and offer advice if I'm not doing it right. I'm going to downgrade from 1.8 as suggested.

Interesting that removing the plastic HDMI module cover makes the issue go away which sounds slightly different than the problem we have with RC version 1.8 installed in which you can't even get 1 meter away before the video scrambles. Question do you have hardware decode option turned on or off in DJI Go settings?