Techniques are disclosed to regulate an output of a power converter. One example power converter controller circuit includes a line sense input to be coupled to receive a signal representative of an input voltage of a power converter. A feedback input to be coupled to receive a feedback signal representative of an output of the power converter is also included. A drive signal generator is also included to generate a drive signal coupled to control switching of a switch to provide a regulated output parameter at the output of the power converter in response to the feedback signal. The drive signal generator is coupled to receive a plurality of inputs including the line sense input and the feedback input. The drive signal generator is coupled to latch the power converter into an off state in response to a detection of a fault condition in the power converter as detected by the plurality of inputs if the power converter input voltage is above a first threshold level. The drive signal generator to be unresponsive to the signal representative of the power converter input voltage while the controller is regulating the output parameter at the output of the power converter.