Gaming PC help

Came home PC wouldn’t boot up windows . Took pc apart assuming it’s the power supply because we had a power outage that day .

Got a new PSU for ATX but my mobo is ITX does that matter ?

I set it up securely and properly , but the mono gives me a red light then yellow then green .

GPU fan spins for one second then stops PSU fan never starts spinning ?

I record a one min video that shows the failed post can’t post it here but if anyone can help dm me I’ll send the video I feel like y’all can fix this on sight