i did a setup like this with the 250btc and fried alot of boards, pcie barrel jack with an adapter to power the 8pin from the same pcie cable from the breakout board. i just ended up buying small psus to run the boards but i recommend using the power plug from the pico 4 pin to power cpu even thought it will draw more from the pico, hopfully the cpu is a low power one so you wont require the 8pin. i also think that these motherboards are built way too cheap and the power is too unstable from a pcie for a board like this, if it was a gaming board then it would have better components and would be able to take that power. just my thoughts tho