About two weeks ago, my EX-21 stopped while I was cutting a made-to-order project. I switched saws and finished the project. Yesterday I got a chance to start working on it. It had to be something electrical, so I began testing at the power outlet and worked through all the electrical parts. Everything worked as expected. The last thing I tested was the motor, and it was OK, so it had to be the controller board. I replaced the board with an old one I had, and it is back online.
While disassembling the saw, I realized I needed to be careful with the plastic parts because if I broke one, I might not be able to get another one.