Question My PC won't turn on after I swapped out my motherboard. Help?

Jan 5, 2021
I decided to do a motherboard swap recently for further upgradability, however after I had reassembled everything how it should be, plugged in my cables, and tried switching on my power supply nothing happened. No power supply fan spin, no fan spin after I tried to turn the pc on itself, not leds on the motherboard, or anything. My new motherboard is the MSI b450 max bazooka wifi and I am unsure if the motherboard came defective or if my power supply is defective. It is hard to believe it could be my power supply as just last week it was operating fine. Is there any other things I can do to troubleshoot this problem before I ask for a replacement motherboard. Are there any switches or buttons I need to press? Is there a specific way I need to plug in my cables? What are all of the essential cables I need for the power supply to turn on? Thank you.