Question PC Will not boot with out-of-the-box parts (faulty psu/cpu?)

[oRdinaryTOMS]

Today I received:

Ryzen 7 3700x CPU
ASUS TUF Gaming B550M-PLUS (WiFi 6) Motherboard
Crucial Ballistix 3600 MHz DDR4 DRAM
EVGA SuperNOVA 650 G3 GOLD PSU

I am re-using my 1660 6G GPU and my generic Seagate storage for this build.

I installed everything to the best of my knowledge, plugged in the PSU and flipped it's power switch (the case I am using is a very outdated NZXT and the motherboard has no connecters that support the case's power button).

Upon hitting the power switch, the mobo lights up and so does the little LED on my graphics card, but the pc does not boot or give any indication of being on at all. The display and peripherals stay dark. The Wraith fan does not spin and it's LEDs do not light up.
RAM is in slots 2 & 4.

• I have tried reinstalling my old EVGA 500W power supply to see if my new PSU was faulty, but it gave me the same result.
• I removed the cooler and made sure the CPU pins were not bent.
• I tried looking for connecters for my case's on button, but was only able to find a 4-pin male end on the mobo that is not compatible with the 3pin female connecter on the case.
• I am very confused as why this could be happening, as I am confident that the mobo does not need a BIOS update as per PC-PartPicker's given information.
• The mobo's rbg is lighting up and the gpu LED being on tells me that the mobo is receiving power, and so is the GPU.

I am not sure what to do from here, any helpful information would be appreciated.
Please let me know if you need any pictures or further explanation.
Thank you.

 

[rocktalkrock]

Did you try booting your setup outside the case before mounting the motherboard inside the case?

 

[oRdinaryTOMS]

Did you try booting your setup outside the case before mounting the motherboard inside the case?

Yes, with both power supplies and limited components on the motherboard. I removed everything as far as one RAM stick and any and all peripherals. I will try clearing CMOS and flashing the newest BIOS to the motherboard through a USB stick when I get home, though I doubt that is the issue.