Fan problem looked everywhere

[Lazyhorse]

I just build a new system for my little brother.

specs: 

tommahawk b450 max 2 mobo

ryzen 5 500

corsair rm650 psu

fans are the fractal 3pin dc fans that came with the case

 

problem is the case fans spin at 900 rpm max

I tried different fans from my own pc same problem

I flashed the bios

the settings are set to dc and max power (also used the all fans full speed button)

I tried different headers on the mobo

they are directly plugged in the mobo so no controller

 

I have the same mobo on my own pc and the fans spin alot faster on mine

 

any ideas at what could be wrong?

If I forgot any needed info please tell me

[Lazyhorse]

Is it normal for dc fans to only spin at 900 rpm? Id I plig in pmw fans they go up to 2500 rpm