A circuit for detection of an HDMI source device to an HDMI sink device through an HDMI sink connector without regard for the activity state of the HDMI source device has a pull-up resistor having first and second terminals with the first terminal coupled to a DC power source. A switching device is coupled between the pull-up resistor's second terminal and ground at a circuit node. The switching device is switched on to couple the circuit node to ground when power is applied to a control terminal thereof from the HDMI sink connector power pin, and being switched off otherwise. The circuit node is coupled to a DDC/CEC GROUND pin of the HDMI sink connector. The circuit node is readable as a binary signal to indicate the presence of a source device to the HDMI sink connector, wherein the node exhibits a logic low signal when either the node is grounded by the DDC/CEC GROUND pin connection to a source device or when the switching device is switched on. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.