A portable computing device (PCD) can control the operating state of a component within an accessory. For example, an accessory can have some components (e.g., a video processor) that are used for some operations but not for others. A PCD can determine whether a particular component will be used and can instruct the accessory to set the component to a desired state, e.g., powered up when in use and powered down when not in use. In some embodiments, the PCD can use status information provided by the accessory in determining a desired state for the accessory component. For example, in the case of a video converter accessory, if no display device or other video receiver is connected to the accessory, a video processor within the accessory can be powered down.