Question New PSU knocks out all lights?

Jan 25, 2022
So today my new PSU arrived (be quiet! System Power 9 600W) and I spent some time replacing my old one, then once I finished and connected my power cable and turned the switch on, the entire houses lights in every room just went dark, managed to get them working again with some fiddling. the strange thing is that sockets still worked. I'm also extremely worried it might have fried my components. What happened?
Yes, its fine now, after digging around to find the source I noticed a rouge screw kicking about the bottom of the case, I took it out and the pc turns on as normal. Crazy what a single misplaced screw can do
What i would do to double check is... Connecting big load like 1000-2000 watt Load in series with PSU and try to Turn it on... If That load works perfectly and PSU doesn't.. means PSU's input side is shorted somewhere in PSU (mostly i have seen is due to Bridge Rectifier or APFC circuit)
If Load doesnt work and PSU works.. every thing is fine..., If Both doesn't works.. (check all cables) means PSU is Open Circuit from inside... Means Dead...