A tutorial to the model-based diagnosis of analog circuits with the artificial intelligence tool CLP(R) is presented. The general framework, called the Constraint Logic Programming Scheme is briefly introduced, and the CLP(R) language which is an instance of the CLP Scheme is described. Modeling of electronic circuits is described in details, starting with models of typical circuit elements (resistor, capacitor, op-amplifier), followed by the general CLP(R) model of an electronic circuit.