Originally Posted by keropi
got a blue dev ps1 as well, but no psu for it
Have you tried using one from a normal ps1? as far as i remember all ps1 consoles have the same shape psu board with the same connector to the motherboard so any should work in the dev version too.
Get a psu board from an early ps1 and you will be fine as the blue dev kit uses the same board as the early retail unit. The green dev kits were the later models.