b450 tomahawk

Hi I just built a new PC, I’ve made sure all the cables are in ok and I’ve unplugged them all one by one attempting to fix the issue. I have a 500W power supply and a B450 Tomahawk max motherboard. The pc starts up for a second and the fans start spinning, but then they stop. Can anyone help...

Hey all I got a 3700X from OcUK when they came out last year and for a while now I've been getting crashers in games at default motherboard settings and its failing prime95 blend test within 5 mins and bsoding on Small FFT within 60 seconds temps are fine I have a Arctic Liquid Freezer II on it...