Myg cousins Zinc Eco electric scooter keeps throwing an E1 error code and fails to detect the speed at which it is moving.

It was fine but was weak and the motor sounded gritty, so I stripped it, cleaned it from all the sort and metal fillings that had accumulated and replaced the magnets, which I removed to clean. One magnet was shattered, so I didn't put the shards back in.

Now, no matter what i do, whether I reset it, disconnect and reconnect stuff, press buttons or anything, it still throws an E1 error code the moment I touch the throttle, and soon shuts off.

The user manual doesn't mention any error codes whatsoever, so I'm completely stuck...

Any help is appreciated...