The increase of complexity on integrated circuits has also raised the demand for new testing methodologies capable to detect functional failures within circuits before they reach the market. Hence, this work proposes to explore the use of homotopy as a tool for testing a basic analog circuit. The homotopy path is influenced by nonlinearities from the equilibrium equation of the circuit; this situation can be used to infer faults by detecting changes on the homotopy path. The concept was explored using numerical simulation of a simple test circuit; then comparing results for the circuit with and without faults, obtaining modifications on the homotopy path like: the final point, number of iterations, and the number of turning points.