An electrosurgical generator includes primary and test sources. The primary source supplies a primary signal and the test source supplies a test signal. The electrosurgical generator includes an output circuit and an abnormality detection circuit. The output circuit is electrically coupled to the primary and test sources. The output circuit receives the primary and test signals from the primary and test sources, respectively. The output circuit is electrically coupled to a load to supply the primary signal thereto. The abnormality detection circuit is electrically coupled to the output circuit to detect an abnormality therein as a function of the test signal. The abnormality detection circuit can also determine a location of the abnormality within the output circuit.
