Saturday, I crashed my chair at full speed and broke the footrest posts. But I cannot claim all the credit--that goes to the #&$^#@^ yard sale sign that was planted by the sidewalk and which blew into the controller and got caught under my arm as I passed.
After a while, when I stopped again, the chair would not move. There were seven battery lights flashing. I turned it off and on, there was one speed light flashing. I looked in the manual and found a quite vague, and less than a helpful hint. On a whim I looked at a later model's manual and found a slightly less helpful hint.
Eventually, I just started pressing buttons to try to get something more out of it and when I pressed the horn button, two speed lights were flashing. So I pressed it again and the seven battery lights started flashing. So I pressed it again and again and again and nothing more happened.
Finally! We're getting somewhere!
Going by the newer model's manual, it definitely had to be the controller, and not just about everything else as the "correct" model's manual says. I opened it up and found the cable to the joystick had become disconnected. That's it. The joystick. THE. JOYSTICK.
I plugged it back in, noted that there was zero force required to plug it in. (I almost thought I was merely imagining I was plugging it in.) And there is nothing to keep it plugged in. No detent, no latch, no nothing. Not even nothing! I did not have anything at hand to secure it so I just put it all back together and tried it and there were no more errors. (I'll have to find something to finish that surgery later.)
Unfortunately, that's it. End of story. no more drama. Nothing about how I scolded the sign owner for his thoughtlessness in placing the sign, let alone finding the owner. If I had found him, he would have been thoroughly and roundly scalded by the scolding I wanted to give him. I may have even demanded he pay for the damage.
Anyways.
The gist: If you get seven battery lights, try turning off the controller then on again. If you get one speed light, press the horn button, get two speed lights, press the horn again and get seven battery lights, then maybe your joystick became disconnected. A T10 driver will open it up and you can plug it back in and put tape over the connector to hold it in place. Given the material, I doubt green glue would work at all--just won't stick. Or, you could replace the connectors with more secure ones, such as locking types...
Have fun...
ps, I discovered that not all Torx T10 drivers are truly T10 drivers. Some are T12 regardless of what they are marked as. Especially in America. YMMV.