Case fans sometimes start, sometimes do not on reboot

[Mcteazy]

I have a strange problem with some new noctua af14a I've installed on my case.

Sometimes all 5 will start in powerup, sometimes only the rear can does.

If I set fan speeds to max in bios, all will run at full speed.

I have a z87-d3h from gigabyte and a rosewill 550w psu.

Thanks!

 

[popatim]

Make sure the minimum fan speed is set at 25% or above in the bios/fan curve