DC fans not working properly

[RainingTacco]

So i've installed two PWM controlled fans, using Noctua NA-SYC1 splitter on one PWM/DC fan header on B450 Mortar[sys_fan2]. It works like a charm, but when i tried to install two non-PWM fans[fractal design x2 gp-12] using the second same splitter[they come in double package] on sys_fan3, i can't control them either by using PWM or DC mode on motherboard. I thought 4 pin and 3 pin are compatible with each other?

[Streetguru]

15 minutes ago, RainingTacco said:

So i've installed two PWM controlled fans, using Noctua NA-SYC1 splitter on one PWM/DC fan header on B450 Mortar[sys_fan2]. It works like a charm, but when i tried to install two non-PWM fans[fractal design x2 gp-12] using the same splitter on sys_fan3, i can't control them either by using PWM or DC mode on motherboard. I thought 4 pin and 3 pin are compatible with each other?

Does DC control work without the splitter?

[RainingTacco]

Ok it works with just one fan and no splitter. But why? Seriously i have to buy 2x3pin splitter?

[WoodenMarker]

27 minutes ago, RainingTacco said:

Ok it works with just one fan and no splitter. But why? Seriously i have to buy 2x3pin splitter?

No a splitter is just wires so the 4pin splitter just has one unused pin and works the same as a 3pin splitter.

What rpm are the Dynamic X2 GP-12's running at? Did you set a manual curve?

Make sure you press the apply / save button and saves motherboard settings.

[LogicalDrm]

5 hours ago, RainingTacco said:

Ok it works with just one fan and no splitter. But why? Seriously i have to buy 2x3pin splitter?

Do they work if you switch splitters around? Or headers? Trying to pinpoint issue, which could be bad splitter.

[RainingTacco]

Lol i've switched to other splitter, connected fans in opposite order, and voila somehow it's working. Weird... Dodged a bullet with wasting money on 3pin splitter.