NOVELTY - The fault-diagnosis system has solar cell string that has positive and negative electrode input signals when connected to positive and negative electrodes. Waveform observation apparatus (125) observes positive and negative electrode output signal. Diagnostic apparatus (128) estimates fault location. Storage unit (135) stores string length which is distance between positive and negative electrode. Calculation Unit (139) estimates distance from electrodes to fault location and adds to string length information based on electrode reflected wave arrival time.    USE - Fault-diagnosis system used for estimating and diagnosing fault location of solar cell array.    ADVANTAGE - The manufacturing cost of the system can be reduced in significant manner, the solar cell string is very small about the signal generation device and the waveform observation apparatus. The fault diagnosis of the solar cell module becomes easier by the calculation result of numerical formula to pinpoint the fault location. The fault diagnosis of the solar cell string is easier, even if the fault location is in the vicinity of the center portion. The electrostatic capacitance can be increased uniformly with respect to several photovoltaic cells, due to the structure of the electrically conductive substance. Since the conductor is grounded, the electrostatic capacitance between the conductor and the solar cell module can be increased.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a fault diagnosis equipment;    (2) the fault diagnosis method for diagnosing fault location;    (3) a program for performing fault-diagnosis method;    (4) computer-readable recording medium storing program for diagnosing fault location; and    (5) a to-be-diagnosed body.    DESCRIPTION OF DRAWING(S) - The drawing shows the block diagram of fault diagnosis system. (Drawing includes non-English language text)    Waveform observation apparatus (125)    Diagnostic apparatus (128)    Storage unit (135)    Calculation unit (139)    Placement unit (143)