[SOLVED] Case fan sometimes (like 1 out of 20 boots) doesnt get turned on on boot

[SoulOfDerp]

Strange, it is not common but it happens once in a while for my PC. They just doesnt spin but only the case fans, my CPU water cooler works and my GPU fans works, but once in a while all the case fans of my PC just doesnt spin when I turn on the PC, restarting doesnt work, it needs a cold reboot to make them work again. And when they work they can work for days and I checked the connection and doesnt seems to be loose.


Intel® Core™ i7-10700KF BOX


MSI MPG Z490 GAMING EDGE WIFI ATX


Crucial Ballistix RGB 32GB (2 X 16GB) DDR4 3200MHz C16 - Black


Toshiba DT02ABA400 4TB 5400rpm 3.5


Kingston A2000 1TB PCIe Gen3x4 M.2 2280


Gigabyte GeForce RTX™ 3070 VISION OC 8GB GDDR6


Thermaltake Toughpower GF1 ARGB 850W 80 Plus Gold TT Premium Edition Fully Modular


Be Quiet! Pure Base 500DX ARGB Tempered Glass ATX - Black


Arctic Liquid Freezer II 360 CPU Cooler


2 x Noctua NF-A14 FLX 140mm Premium Quality Fan

Win10

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

Make and model case?

Make and model fans?

 

[geofelt]

A fan will usually need at least 5v. to turn on.
Check your motherboard fan controller profile for the fan in question.
Set the curve to more than zero to begin with.

 

[Paperdoc]

First question: exactly where are these fans plugged in? IF they are plugged into mobo fan headers, they should be the SYS_FAN headers.

Next: examine the configuration screens for the SYS_FAN headers they are plugged into - see mobo manual p. 35. Since these are 3-pin fans, they should be set (upper left) to DC Mode.

Next: exit out of BIOS Setup. Carefully open your case so you can see the fans. Reboot and WATCH them carefully right away. The NORMAL process is that all fans should start up at full speed right away, then slow down after a few seconds. If these Noctua case fans do that and THEN stall, the problem is that the headers are set to run them too slow at low temperatures. IF that is what you see, go back into BIOS Setup to the configuration screens. For EACH header for those fans, on the graph of fan speed vs temp, move the minimum speed dots for the lowest temps up to a higher speed. After setting both, remember to use Esc to return to Main Menu, then F10 to get to the Exit pop-op. Click on YES to SAVE your new settings and reboot.