I was trying to update the SC to the latest firmware tonight prior to sending it off to its new owner. In the middle of the update, the screen went black and nothing. I waited quite a while. Nothing. Could not turn it off. Hooked it up to DJI Assistant 2. It recognized the SC and I tried to back it down to the previous firmare. The update failed and now DJI Assistant 2 doesn't recognize it. Cannot turn it on. Any suggestions? Arrgggghhhhhh.