Mini-ITX fan starts then stops when using pico-PSU.. why??


What's an ITX?
Original poster
Feb 15, 2020
Gigabyte AORUS B450 mini itx motherboard
Ryzen 3 3200G CPU
Corsair Vengeance DDR4 3600Mhz 8GB
12V 10A 120W AC-DC converter
150w & 250w PICO PSU

When I start PC, CPU fan will spin, then stop. Thought 150W PSU too small maybe, got a 250W, same thing. Connect my full size tower PSU to the board, powers up fine. But I dont get it; I have ZERO connected to the motherboard other than the CPU, CPU fan, and the RAM. What gives??


John Morrison. Founder and Team Leader of SFF.N
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
Is there a short circuit somewhere in the wiring - that seems to be the behaviour for that.