UPDATE: I fixed it!! It was the PSU.
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.
Any ideas?
Specs:
AMD 7800X3D
ASRock B650E PG Riptide WiFi
Sapphire Nitro+ Radeon RX 7800 XT
2 x 16GB Crucial DDR5 RAM
Seasonic GX-850 PSU
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?
Disconnect the psu from all the devices, use a wire or paperclip to short the green wire on the atx connector to black wire.
If the psu doesn’t turn on, that’s where your problem is. If it does, it may be your mobo or something else.
If your atx connector doesn’t have a green wire, google for which pin it is to turn the psu on manually.
This helped me once: remove ram, hold power button for 30 seconds, insert ram, insert power, try to power on.
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.
Good luck!
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.