Hi,
Connected phone to USB under the RC (removed the usb connected from the left side of RC). Rc started beeping with red light but 4 green lights.  Powered on the air and RC connected and DJI app came up with Fly zone update which it started.  While transmitting to the drone, it would not move from 22%.  Shut down everything and noticed that the RC even though it had no power, the red light was on.  It won't even do a battery check.  Tried to power on the RC, but will not turn on.

Any advise would be much appreciated.  Thank you.

If the controller has a red LED then you need to link your controller, your Mavic Air will also have a yellow light on the rear of the drone.Hope this helps...
Try this thread...
https://forum.dji.com/thread-136748-1-1.html

Tomcatuk Posted at 7-26 22:36
If the controller has a red LED then you need to link your controller, your Mavic Air will also have a yellow light on the rear of the drone.Hope this helps...
Try this thread...
https://forum.dji.com/thread-136748-1-1.html

Thanks, will give it a shot, if I can even power on the RC.  As of now, it still shows solid red and pressing to check battery level or power on, does nothing.  

Hi, thank you for reaching out and we're sorry for the inconvenience caused. Can you please try to charge your RC, once fully charged, try to connect it to your mobile device and perform the RC calibration. Once done, try to relink the Aircraft and the remote controller to see if it will rectify the issue. I will be posting an official video tutorial below. Please keep us posted. Cheers!

It's possible rc charging receptacle normally connects phone that you've alternatively connected elsewise? This would include a suspect cable with its termination plugs &  the mating receptacles on devices.
Did you run into problems assembling rc & phone using the 40cm short flat cable factory provided?

The firmware flash evolution that you claim stalled, how long did you wait on stall? 30min?

Thank you all.  After a couple of hours, went back to check on the RC and the red light was gone.  Charged the RC and setup my air again and everything worked flawlessly, including the fly zone database update.

Glad you got it sorted

georgieB Posted at 7-27 14:09
Thank you all.  After a couple of hours, went back to check on the RC and the red light was gone.  Charged the RC and setup my air again and everything worked flawlessly, including the fly zone database update.

Goodjob!
A warm thankyou for the moderator's absolute pointer 1st crack