There are many reasons for the phenomenon of blackout in Sudan, some of them are the electrical defects in the power generation plants, operation defects, human errors and the out-service plants. The complete blackout affects the mechanical parts in the power generation plants. In the recent years the phenomenon of complete blackout happened many times in Sudan and causes several problems and defects in the power generation plants. First time, complete blackout happened in August 2011, then twice in December 2013, and in May 2015. In 2016 complete blackout happened was repeated three times, and once in February 2017 and once in January 2018. The last complete blackout in Sudan was happened in January 2019.Here Bahry Thermal Power Plant was taken as a case study since it is more affected due to this phenomenon. In unit No. 6, which is steam power plant, both shafts of the high pressure and low pressure turbines were seriously defected. Other defects were noticed in the crankshaft seats and oil rings in high pressure and low pressure turbines.