[SOLVED] How to fix “CPU Fan Error” + unable to press F1 to enter BIOS?

[tellerx3]

This happened all of a sudden. I wasn’t booted out of an overheated CPU while using it. It happened when I just turned on my PC in the morning like everyday for the past couple years. Except this time around I was greeted by the “CPU Fan Error, Press F1” screen.

https://ibb.co/NKLjn0p (the screen)

I managed to get into the BIOS screen by pressing F1 the first time, but panicked so I turned the PC off (noting that the CPU temperature was steadily rising to 68 Celsius in that minute or so I was in BIOS, it doesnt seem like it was stopping). Fans seem to be spinning, so is it the problem with the coolant I’m using?

Now I can’t even press F1 to continue after that first time. (keyboard works on another device). Still clueless on what’s happening even after googling around last night.

I’ve since opened it up and cleaned it all the best I can with compressed air, etc, and without messing with any cables. But the problem still remains. Forever stuck at that CPU Fan Error screen, pressing F1 (or any key) doesnt do anything 🙁

Mobo: z370-plus
Cooler: Corsair H80i v2

 

[rgd1101]

recheck the connection to the cpu fan header on the motherboard
the pump/fan working on the water cooler?

 

[Paperdoc]

The error you got indicates that whatever device is plugged into the CPU_FAN header is sending NO speed signal to the header. The header interprets that to mean that there is NO way to cool the CPU, and has taken the option to refuse to let you start up until this is fixed.

IF what is plugged in there is a fan on the CPU cooler radiator (or another fan?), check that is does run, and verify that it has a good connection to the header. More likely, however, is that the item plugged into the CPU_FAN header is the PUMP unit of your AIO cooling system. And THAT may be what is NOT woorking any more. It can be hard to tell if a pump is actually running. But most do vibrate a little when running. So, with the system turned off, touch the pump. Hold you finger there and try to turn on your system. Does the pump start to do anything? If it seems totally silent but you still get the screen warning, then the pump is dead.

 

[alexbirdie]

You only wrote z390-plus. I found one from ASUS:

TUF Z370-Plus Gaming

Thhis board does have following connectors:

1 x Aura RGB Strip Header
2 x USB 3.1 Gen 1(up to 5Gbps) connector(s) support(s) additional 4 USB 3.1 Gen 1 port(s) (19-pin)
2 x USB 2.0 connector(s) support(s) additional 4 USB 2.0 port(s)
2 x M.2 Socket 3 with M Key, type 2242/2260/2280 storage devices support (SATA mode & X4 PCIE mode)
6 x SATA 6Gb/s connector(s)
1 x CPU Fan connector(s) (1 x 4 -pin)
2 x Chassis Fan connector(s) (2 x 4 -pin)
1 x S/PDIF out header(s)
1 x 24-pin EATX Power connector(s)
1 x 8-pin ATX 12V Power connector(s)
1 x Front panel audio connector(s) (AAFP)
1 x Clear CMOS jumper(s)
1 x System panel connector
1 x W_Pump+ Header
1 x AIO PUMP Header

Found following description for the cooler(https://manuall.de/corsair-hydro-series-h80i-v2-cpu-kuhler/):

• Connect the pump power cable to the
CPU_FAN header on your motherboard.
• Connect the fans to the two connectors
coming off the pump.

As you can see in the above description, the cooler-cable seems to be a 3-pin-cable. Could it be, that it is not correctly mounted on motherboard-CPU-FAN-header. Please look into the h80i-v2-description ( link above).

 

[Paperdoc]

I'll explain the 3-pin fan connector coming from the Pump unit of the Corsair H80i V2. When dealing with FANS, if you connect a 3-pin fan to a 4-pin mobo fan header that actually is using the new PWM Mode for speed control, That fan only runs full speed all the time. Well, in the H80i system, the PUMP is designed to run full speed all the time. So they tell you to connect its 3-pin fan connector to the mobo 4-pin CPU_FAN header, plug the rad fan into a cable from the pump, and connectv a third cable from the pump to a mobo USB2 port. Then you must download and run the Corsair Link software utility. That utility uses the USB cable to communicate with the pump and control the rad fan via that link. (The CPU_FAN header does NOT control the rad fan speed, and what it tells you is the CPU FAN speed is really the PUMP speed becasue that is what it plugged in there.) Corsair Link can tell you both the PUMP speed and the FAN speed separately if you look there. I would bet it also ensures that the CPU_FAN header is always sending out to the pump a full 12 VDC power supply so it runs full speed as designed.

I'm sorry, I missed the fact you are using a H80i system. NOW I really grasp what is going on. IF you connected it as directed (cable from pump to CPU_FAN header, and rad fan to pump output cable) then the FAILED unit that is not feeding a speed signal to the CPU_FAN header IS the PUMP!