I had a recent failure of my Grizzly dust collector remote relay switch. The screws that hold the circuit board for the push buttons/remote in place came loose from vibration, and got into the relay and shorted out the board. Grizzly replaced the box under warranty and everything is fine, but I thought I might point it out. If it hadn't been under warranty, it's a $150 part. You could of course change it to on/off switch for the relay, but if you want to remote switch or timer part, you gotta buy the whole box.
It's very easy to check the screws if you have one to make sure they're not loose. I even noticed the push buttons I use occasionally seemed to be harder to push right before it failed, but didn't even think about the board being loose behind the panel.