GDEMU and Pico PSU - I really need some help.

[MoeFoh]

Diagnosing with a thermal camera on the motherboard could be useful here, but you won't have that equipment. The next obvious step would be r&r (remove & replace) with a known good motherboard.

On the original motherboard you could reflow the power pins.

Recap kits are available for the blown power supply and motherboards.