I'm having very crooked horizon issues and was advised to reflash the firmware but am not seeing how to do this or where I can download the firmware manually.

When I connect the iPad to the P4 and hold the hat icon in the top  right of the DJI Go App for 10 seconds and when I let go it says,

Product: Phantom 4
Current Version: 01.01.0410
Get Firmware Version Faled
Select Firmware Version: None

Go to the DJI Phantom 4 page.   Scroll down to the bottom where the downloads are.   Download DJI Assistant 2 v1.0.4 and install it on your home computer.

That program will allow you to download and install the latest firmware using a USB cable between your computer and the craft.

Thank you.  I will try it when I get home from work.

Hello Youthman, it would be easier to reflash the firmware by using the DJI Assistant 2.

I'm downloading the software now.  Will post results.

Ok, I installed the software, plugged in the P4 to my computer via USB and powered it up but nothing is happening.  

Did it install the USB drivers associated with Assistant 2 ? If not then try re-installing, if so then try rebooting computer. Also try repowering aircraft and wait for flashing yellow status indicator lights (the rear LEDs) before starting Assistant 2.

Ok, the "Phantom 4" showed up in the software and I clicked on it and it began to install the firmware in the P4.  After it finished installing, it said to restart the P4.  After restarting it, it said, "Lost Connection, Ensure flight controller is connected to your computer".  So I disconnected the USB from the P4 and plugged it into the Controller but nothing happens.  Not sure what to do from here.

Yes, it installed the USB drivers.  I shut down the P4 and closed DJI Assistant and turned back on the P4.  Then I opened DJI Assistant and it shows the P4 so I click on it.  

It says that I have the current Firmware installed 01.01.0411

Do I need to update the controller somehow?

Try connecting RC to a wifi enabled display device. Powere up RC, power up aircraft and wait for it to initialise. LED on controller should turn green. then connect display device and open up DJI GO (2.8.3). It may prompt you to update the RC via the wifi if needed. If so then update controller. Once done reboot all...RC , then aircraft, then run DJI GO.

Controller needs to update to V1.6 (controller firmware latest).

In the DJI Go App, it says

App Version 2.8.3
Aircraft Version 01.01.0411
Remote Controller Version 1.6.0

So it looks like I'm updated.

Headed outside to do a quick test. Will calibrate my compass while I'm outside.  Will report back in a few minutes.  Thank you for your help.

Youthman Posted at 2016-6-7 23:45
Headed outside to do a quick test. Will calibrate my compass while I'm outside.  Will report back in ...

Remember to calibrate Sensors (in assistant 2), IMU, Gimbal, RC & Compass

I did the sensor calibration in the Assistant 2 and Compass outside but did not re-calibrate IMU or Gimbal before flying.  Images were still crooked.  I brought it back inside and will calibrate IMU and Gimbal again.

When calibrated adjust horizon level by holding 'C2' button (rear right on controller) operated and use right hand wheel to adjust. For me it seemed to hold horizon well after this.

I just calibrated the IMU.

IMU1 is 0.000
IMU2 is 0.001
Gyroscope Bias is 0.003 and 0.000

Do I need to go outside to calibrate the compass?

Probably best, less chance of interference, and don't hold controller next to aircraft.

Unfortunately I wasn't able to test it before I had to take my daughter to practice.  I'll take a flight in the morning.

As a side note, am I supposed to be receiving email notifications when someone replies to a thread I start?  If so, I'm not.

Here was a photo I took tonight (before calibrating the IMU).  Hopefully calibrating the IMU will fix it.