So I just built my first PC in like 20 years. Everything was going fine, I was installing Windows and got to the network setup step and my wifi was having trouble staying connected. I figured it was because I hadn't set up drivers yet, so I thought whatever, no problem, I'll just move it by my router and plug in an ethernet cable.
So I powered off and moved it, and...dead. Nothing is happening when I hit the power button. No fans, no lights, nothing. I've made sure no cables got jiggled loose or anything. Maybe I shorted something somewhere on the motherboard? I can't see anything without fully disassembling and having to rebuild it. I really don't want to do that, but I guess I'll have to unless I'm missing something obvious. I'll test the PSU tomorrow but I doubt it's that, these are all brand new parts.
It might sound silly, but did you make sure the PSU power switch is turned on? Have you tried jumping the front panel pins on the mobo instead of using the power button? Made sure cables are securely plugged in on the PSU as well as the mobo? Tried plugging it back in to the original outlet that it worked at before?
I did try all those things as a sanity check. I also tried unplugging everything from the PSU and motherboard and plugging them back in and still no lights :(
Yes, for standard 20 or 24 pin PSUs this is fine (which is almost assuredly what you have if you're building your own). Nonstandard ones, like what Dell or HP use, rarely work like that.
If there isn't a single hint of life it does sound like PSU. If something is defective and going to die, then it's liable to do it sooner rather than later, brand new or not. Unlikely from Seasonic but these things happen.
Could be motherboard. Could also be something silly like the front panel header for the power switch came off!
Not applicable if you are US, but if you are in a country that has individually fused plugs, like the UK, then check the fuse in the power cable or use a different one.
Check your screw standoffs/spacers. Make sure that they match your motherboard exactly.
Most cases come with them preinstalled for a micro ATX board. Certain motherboards- like this one, it appears based on a stock photo- need one of those removed before installing the extras.
I admittedly haven't had much time to mess with it, but I confirmed the PSU is working, so I suspect the motherboard is fried. Still need to confirm that before I order a new one, and figure out why it happened so I don't do that again. I'm hoping my CPU is still fine.
I really appreciate everyone's suggestions, helped me narrow it down a bit
Just because the PSU works on another system (or God forbid, those awful "testers") doesn't mean that it's fine. PSUs tend to fail in weird, unpredictable ways
If you have (or can borrow) another working psu and working moba, swap them with the ones for your new ps. Your psu with the other moba, and your moba with the other psu. That will tell you which component(s) are the problem.