1. A method comprising: measuring, by a controller, a plurality of values of a feedback voltage from a power control system over a period of time, the power control system being configured to provide an output voltage, the feedback voltage being associated with the output voltage, a response time being estimated for the feedback voltage varying from an initial lower voltage to a higher voltage at a stable level based on one or more properties of the power control system, the period of time being predetermined based on the estimated response time; determining, by the controller, a rate of feedback voltage change based on the measured values of the feedback voltage and a duration of the period of time; determining, by the controller, that the determined rate of feedback voltage change is smaller than a threshold rate of change; and in response to determining that the determined rate of feedback voltage change is smaller than the threshold rate of change, transmitting, by the controller, a fault indication signal to the power control system.