So far, more than 200 V94.2 gas turbine units have been installed in Iran, which make up about a quarter of the country's total installed power plant capacity. On the other hand, reducing operating costs and increasing productivity due to the entry of the private sector into this field is one of the other requirements of today's electricity industry in the country. Therefore, any action to accurately and quickly identify the defects of the mentioned rotating equipment can play an important role in achieving the above goals. In the V94.2 power plant units, there are various parts, among which there is a system called the cooling system, which is responsible for cooling the generator as well as the oil in the turbine and compressor lubrication system; In this book, it is planned to use the vibration data of the cooling fans of the Qain power plant, and in the first step, each of the defects created is created separately on the fan, and by installing the sensor, the vibration values of speed and acceleration at different frequencies Measure by VIBPRO V4 analyzer and then use the fuzzy logic method as a troubleshooting system in the next step.