CPU Fan Error after Installing Ram

Name Dropper First Comment
edited September 2021 in General Discussion


I had an issue with m'y computer not sending a display signal and micro center determine the issue to be the ram, which they replaced. When I booted up the computer at home, I'm now getting a "CPU Fan speed error detected". I don't know a lot about PC builds, but it appears to be installed correctly onto the motherboard. In the Bios, it has a "N/A" under the CPU fan in the fan profiles. There's a CHA2 Fan that's spinning and a AIO Pump. Does anybody happen to have any advice on how to fix this? Thanks in advance!

Best Answers

  • JS_MC
    JS_MC admin
    First Anniversary 5 Up Votes 5 Awesomes First Answer
    Answer ✓

    Hey @wzjy47

    Could you tell me a bit more about your system? It seems like you've mentioned having an AIO. If that's the case, you'll likely need to change your fan settings. Instead of having a fan speed, you're looking for a pump speed. You might need to change the setting in your BIOS. The good news is that it does recognize the pump and your CPU temps are good. It's likely that the fan in the CPU fan header was moved when the RAM was swapped.

    If you want to remove this error. Just make sure a fan is plugged into your CPU1 Fan header.

    The important bit for an AIO is that it is receiving a constant RPM or power level.

    Hope this helps, but please let me know if you have any other concerns.

  • PowerSpec_MichaelB
    PowerSpec_MichaelB ✭✭✭✭✭
    First Answer 5 Insightfuls First Comment 5 Awesomes
    Answer ✓

    This is going to be an error that you'll see on ASUS boards if CPU_FAN1 is not occupied with ANY fan, or if the fan that is currently plugged in is no longer functioning. Make sure you have a fan plugged into this header. Alternatively, you can disable this error detection though it is not recommended if you have a fan plugged into this header and are still getting this error. The steps to ignore this error can be found below:

    • F2 to boot into BIOS
    • F7 to enter Advanced Menu
    • Navigate to Hardware Monitoring
    • Scroll Down to CPUFAN_1 and change monitoring to Ignore.
    • Save Changes & Exit.
  • PowerSpec_MikeW
    PowerSpec_MikeW PowerSpec Engineer
    5 Insightfuls First Anniversary First Comment 5 Awesomes
    Answer ✓


    You're good to go. Board is always going to check the CPU_FAN header, but with AIO's you'd rather it be on the dedicated AIO_PUMP or W_PUMP header. Reason being CPU_FAN is thermally controlled, AIO_PUMP and W_PUMP are not. You don't want the board to throttle the pump. Solution usually is to put the radiator fans on CPU_FAN, but this have may have been placed on CPU_OPT or a chassis fan header. Most likely the tech moved the AIO PUMP off CPU_FAN and didn't move the radiator fans over. Not an issue you need to worry about.

    So far as electrical issues. I'd say you found one if the PC wouldn't POST on that outlet only. However, it's unlikely this killed your RAM. Power supply should be the first thing to go, it's the first in line.


  • wzjy47
    Name Dropper First Comment
    edited September 2021

    Thanks for the feedback! Attached are a few more pictures...I purchased this computer used about a year ago mainly for the graphics card and honestly don't know much else about it. It looks to me like there's an AIO pump installed over the CPU and it appears to be connected and running. The BIOS does show and AOI pump and appears to be monitoring its speed. When I changed the BIOS to "ignore" the CPU Fan Speed, the computer boots up properly. Does this mean that if its monitoring the AOI pump, then I'm good? Would installing the RAM, reset this setting in the BIOS?

    Another odd thing, which I'm not sure is related, but I could not get this computer to load windows on a specific outlet. It has been working fine for the past year, but then all of a sudden I didn't get any video signal. When I moved to a different outlet, it booted up fine and appears to be running without any issues. This is the original issue which triggered me to take it to Microcenter in the first place, but they determined the RAM was bad. Before replacing the RAM, it wouldn't even log to the screen where you can get to the BIOS. With the new RAM, it got to that screen with the CPU fan speed error. I'm concerned I've got some sort of electrical issue with that circuit and I'd prefer not to fry any more electronics, even though the breaker hasn't tripped:)

    Thanks again for the help and please let me know if you need any additional information.

  • wzjy47

    @TSMikeW Thanks! I'll start chasing the electrical problem now:)

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