pc stopped working, no power to anything, changed power supply, still no power.

hey so i have had my pc for around two years now. the power supply has turned went bad before and i changed it out and everything was good about a year ago. then a couple days ago it just completely turned off. i tried everything but still wouldnt work so i got a new power supply same brand (thermaltake) and did everything but still wouldnt power on. i used an ac voltage detector and the only thing that was going off was the power switch on both positions. i tried unplugging and plugging everything but no luck. i replaced the batter on the motherboard too. i do have a roach problem and there were roaches in it, but its been fine up until now. please help!