Fan problem

[BathSaltZombie]

Built my pc 5-6 months ago.  I have two corsair AF120 quiet edition LED fans for exhaust, on top of case.  And SP120's on rad in pull config in the front.  When i would power on my pc one of the AF fans' led's would flicker for a few seconds before staying on.  This annoyed me but didnt think much of it, this fan quit working completely the other day so i went and bought a new AF120 fan to replace it.  Hooked up the new fan and to my surprise it did the same light flicker as the old fan did, at initial startup.  I switched fan header from cpu_opt to the regular cpu fan header, this time when i powered on there was no light flicker, but i quickly noticed the fan rpm was much higher than the other AF fan, AND the led's were noticeably brighter.  Went into bios to see if i had fan settings messed up but they were all set to 'normal' speed, so i set both of the AF fans to 'silent' mode for the lowest speed setting.  This did nothing as the one new fan was still moving much faster than the other, with brighter lights.  Any suggestions to fix this? im afraid the new fan is going to crap out like the last one because its working so hard.  I am very novice and new to the pc world i'll add, this is the first pc i've built.

 

 

 

z97 mx gaming 5

i5 4690k

gtx 960sc

8gb vengeance 1866mhz

600w psu

corsair air 240 case

windows 10

H105 aio water cooler  

 

[Mug]

*wall of text meme*

 

flickering is normal, my SP140 LEDS flash on at startup it's just the motherboard checking it's shit.

 

 

And because it's voltage control, the motherboard lowering the speed of the fan will reduce the brightness of the led, it's just basic science really.

 

Get an NZXT GRID + for independant control you mug

[TheArmChairGuru]

If your description was accurate, the top AF120s should not be on a CPU fan header at all, neither Optional or cpu.

They should be on a case fan header.

 

The main CPU Fan header in 4 pin config is recognized as the one that cools the CPU by the BIOS, so if it detects a need for more cooling, it will ramp up the speed of the fan on that header.

The only thing that needs to be plugged into the CPU fan header is the fan that cools the CPU.

 

If you have a CLLC, you need to follow the manufacturer's instructions but generally either the pump (usually) or the rad fan needs to be plugged into the main CPU fan header and the CPU_OPT header is for the other one (either rad fan or pump).

 

ALL other fans need to be plugged into the case fan header(s) or dist. blocked into the case fan header.