To solve the diagnostic problem in static mode, it is proposed to use compensation of nonlinear elements with both unknown and known parameters. This reduces the diagnosis of a nonlinear circuit to the basic task of diagnosing a linear substitution circuit with multiple experiments. The multiplicity of the experiment and the calculation of the substitution circuit is determined by the number of required points of the volt-ampere characteristics of nonlinear resistors and the transfer characteristics of nonlinear controlled sources. The number of measurements in each experiment should not be less than the number of nonlinear elements and linear elements with unknown parameters. Computational costs can be reduced if symbolic analysis methods are used to obtain volt-ampere and transfer characteristics of nonlinear elements in the form of parametric functions. The proposed approach makes it possible to automate the diagnostics of nonlinear elements in a static mode using well-known symbolic and numerical programs for the analysis of linear electrical circuits. An example of finding the volt-ampere characteristics of nonlinear resistors using the developed CirSym symbolic analysis program is given.