According to at least one aspect, a device is provided. The device comprises: a connector configured to electrically couple to an external device and comprising a plurality of terminals including a supply terminal; a monitoring circuit coupled to the supply terminal and configured to apply an electrical signal to the supply terminal and measure at least one of a voltage level and a current level on the supply terminal; a controller communicatively coupled to the monitoring circuit and configured to: determine whether an impedance between the supply terminal and at least one other terminal in the plurality of terminals is above a threshold using the at least one of the voltage level and the current level on the supply terminal; and output at least one message responsive to the impedance being below the threshold.