pico psu boot power up no post

My system only has a 2400g, 2x 4gb Ram, and two 40mm noctua case fans. No LED strips or GPU. One 2.5" 256gb SSD. That's it. The wattage this system should sip is max 120w. AsRock b450 fatality mobo. Just refuses to power on. I'm using Pico 160xt. But my power brick is 156w and doesn't match the...