B450m Steel Legend not posting.

So I Decided to freshen up the cable management on the B450m Steel Legend and my pc and fix the RGB on my pf 240 because the wiring was weird but then now it won't boot its on the 3rd Gen Ryzen 5 3500 which booted before but after I did all this it just didn't work I tried unplugging the rgb changing ram slots pulling the little battery out I've tried a lot of things which haven't worked out and when I plug it in all the rgb lights lit up but then when I pressed the power button the fans didn't start spinning and my gpu fan was going on and off on and off I use so I really would like help.

Issue resolved I ended up being a derp and not plugging in my monitor and my fans for my aio cooler