It's been suggested that our power is dirty but we've had it checked and prior to this we had 3 Yamaha power amps that lasted from 2001 to 2016 and they still worked when we pulled them out

It's been suggested that our power is dirty but we've had it checked and prior to this we had 3 Yamaha power amps that lasted from 2001 to 2016 and they still worked when we pulled them out