I experience this once with my CAV50. I had to unplug the unit to get it to power down. I boxed it up and took it to my local dealer to have them take a look at the switch. Once I arrived at the store and we plugged it in , the power switch worked fine . We assumed it was from the ride down in the car and from maybe moving it around. It has worked fine ever since then.
See what happens over the weekend. Try exercising the power switch from time to time. Maybe you have some type of debris in the switch assembly that might work itself out. It won't hurt to try!
If you still have the same issue , you can call Conrad Johnson Monday and see what they suggest.