I have this problem: My DJI Spark and the Remote Controller are not perfectly calibrated and the Spark has a suttle drift to the left when I am only in forward pitch right stick. I want to reset the controller and Spark so that the settings are back to factory state so hopefully we can make it work a little bit more uh smoothly, ah yeah.

DJI Assistant 2 is required to reset. I just used it to reset and fix a problem with it not flying straight where it was pointed.

Thanks for your quick reply. I downloaded DJI Assistant 2 and was wondering do I plug in the Remote Controller or Spark into my PC with the USB cable?

You connect the Spark with the provided USB cable to the PC.

For the RC have you tried calibrating the joysticks? you can perform that with the DJI Go 4 app and see if the AC still drifts.

Thanks for your quick reply. What I tried doing instead was a manual without a PC. It seems to have worked. What I did exactly was to hold down for 9 seconds the rear power button of the Spark. That action disconnected the Spark to the Remote  

Thanks for your quick reply. What I tried doing instead - was a manual without a PC. It seems to have worked. What I did exactly was to hold down for 9 seconds the rear power button of the Spark. That action disconnected the Spark to the Remote and I re-paired the Spark holding down the power button again for another 3 seconds. Holding down the Remote's Pause, FN, and right rear buttons until the green light began blinking, I re-paired the Spark to the Remote and after flying the Spark quickly in right pitch forward just backward and forward, this hopefully seems to have repaired the right tiltering issue?