Yikes. Does it turn on to the source it was last set to, or does it switch to video?

If you want a work around IF it turns on to the last source, build the turn off macro to switch to an unused input on the Yamaha as the step before powering down the Yamaha....

Has it ever randomly turned on before during the day? Do they have a cat who discovered the joys of watching TV in the middle of the night?