A signal processing system comprises multiple signal processors, each having functional blocks. A control circuit selects one of the signal processors as a target processor, and configures an inspection circuit having equivalent functions to the target processor in a reconfigurable circuit, and retrieves input/output data from each functional block of the target processor to perform inspection on the functional block by using the configured inspection circuit and the input/output data to produce an inspection result. The functional block is replaced with a substitute circuit which forms part of the inspection circuit when the inspection result indicates that the functional block is faulty.