I generally dont have any fluctuation in my area. Basically in my tv cabinet all the speaker wires( 4 atmos and 2 surround 3lcr) assemble in a tight space where i am supposed to keep my avr so some of the wires got squished by my avr as the space is quite tight. I am afraid this could be one of the reason. I have never had any such sudden power surge problem in my area.