I have a high power (6000W) sub-woofer amplifier which has a switch mode power supply. This amplifier only worked few hours before it stopped working and it looks like an issue in the power supply. Amp is connected to AC mains at 240V which drops quite a lot to around 180V sometimes. It is also possible that the frequency is not stable at 50Hz either. Can such fluctuations affect switch mode power supply reliability?