Can any passive devices that use no active electronics (such as a mechanical switch box) be compliant?
Any device which performs processing, amplification, or switching of the HDMI signal should use actively powered electronics to be compliant and perform reliably. As mentioned in the above question, the vast majority of devices can utilize power that is supplied on the 5V line (+5V power) of the HDMI connector to function properly, although we recommend that such devices give the users an optional provision to use an external power adapter. Completely passive, non-powered devices may work in some short-cable length applications, but use them at your own risk, as they may not operate reliably. Even if a passive device works in one configuration, a change in equipment or cabling may introduce failures in subsequent configurations.
