Question Noctua nf-A12 and nf-A14 problems using 'Y' splitter.

[DonoDonato]

Hello,

I've bought theese awesome two PWM fans for my mini-itx case:
Noctua Fan Chromax Black Swap PWM NF-A14 140mm (max PWM speed 1200rpm);
Noctua Fan NF-A12x25 120mm PWM 120mm (max PWM speed 1500).

My motherboard Gigabyte GA-z170n-Wifi has 1 PWM 4-pin for CPU and 1 4-pin PWM for fans.
I've used 'Y' splitter that came with the nf-A12 fan (one end is with 4-pins (master), and the other end is with 3 Pins (slave).

The nf-a12 works on any end, slave or master. But the nf-A14 fan doesnt work neither on one or the other end. When i launch computer it just spins briefly and stops and makes a ticking sound. The other fan spins without problem no mater if he is on slave or master.

nf-A14 works fine alone, if i unplug nf-a12 from the 'Y' splitter.

What am i doing wrong? It should work. Right now , with the same 'Y splitter' i am using nf-a12 and my old case's fan (fractal design define nano s).

Please help!

 

[DonoDonato]

After countless trials i found this setup that sort'off "Works".
Swapped extension cord from nf-a14 to one in the box of nf-a12
Used Y splitter:
nf-a12 (Loud Noise Adapter - slave end of the Y pin).
nf-a14 (master end of Y splitter).
Bios Manual speeds // 1.0PWM per 1C).

Unfortuantely if i go lower (0.75 which would be perfect), nf-a12 silences and ticks and clicks and never starts.

I did not expect bot theese fans to be so noisy. Even with nf-a14 at 700RPM, and nf-a12 at 850RPM.

Also it consntatly tiks. Without loud noise adapter on nf-a-12 it spins way too loud and fast. Tried SpeedFan software it does not detect my motherboards fans.

I messed up when i bought a 2000RPM fan. In some video review someone said 1500max PWM speed, that was good enough for me, that would have worked. Now im in a pickle.

 

[DonoDonato]

After more testing. I've discovered, that the problem is that nf-a12 lowers speed is 500RPM. nf-a14 lowees speed form what i've tested is 600 RPM. Lowe than that they will stop.

THAT would be perfect for PWM. When i set in bios 0.75PWM value 1degree, i can enjoy utter silence with both fans off when i browse. Unfortunately, the nf-a12 starts ticking like hell when it gets close to the threshhold of spining. LOUD.

When i enter a game in 0.75 setup. Bot fans start spining. When i exit. The front intake nf-a14 keeps spining at low RPM's. The nf-a12 stops And it NVER starts again even if i toast my computer by entering a game again. And it does not start even after restart, shut down mutliple times. It's like it rememvers.

So i am using a 1PWM=1'C with fans spining unnecesarry at low temps when browing. Makes no sense of having PWM fans that way.

This instability might be caused by my MB bios... maybe. I will try update it to newest one and see how it works. Maybe fan header will show in SpeedFan app, because now it doesnt show.

 

[DonoDonato]

I've came to conclusion. My CPU fan header is PWM. My System fan header is not PWM (in manual it sais 12v/PWM reverse compatible - whatever that means). That's why my fans were having issues.

My computer had inside a Be quiet pure rock CPU cooler it has a PWM fan that is 2000 RPM. It maches speed of the nf-a12 (2000 RPM max).

I've put the low noise adapter into CPU fan header. Attached Y splitter to it. And plugged CPU fan and nf-a12 to it (nf-a12 got smooth and quit). I hooked nf-a15 to the system fan header (it is stil noisy).

I've actually tried hooking nf-a12 and nf-a14 to the CPu fan's PWM heather - they work fine together. I tried hoooking the CPU cooler's fan to the system fan header - it got loud and obnoxious even just at 1000RPM.

I came to conclusion - the system fan header is bad with PWM fans even if they call it 'PWM reverse compatible/12v) fan header. Sure it works but it makes fan work as regular fans and not as pwm. I know that for sure because the nf-a14 starts spining only at speed of 600RPM on the SYstem fan header. And i've seen ti spin at 550 on the PWM fan header.