Hydro Series H100i v2 cpu_fan error.

[Krehlmar]

Hello! Not sure if bounties are allowed so I wont promise such but I really need some help 

 

So my comp had been working fine for 3+ years now but one day I suddenly get a bios-error that warns me of cpu_fan error.

 

Only the fans are working fine, but it seems to be a problem with the pump/cooler not actually being chilled.

 

What makes this infuriating is that it DID start working again, THRICE, with no change on my end except endless restarting and rebooting in bios trying to figure something out. None of those changes actually amount to anything, since I went back to default plenty of times and was mostly checking out of desperation. Two of the times it was just regular restarts since I was hoping it'd magically work like the first time, which it did.

Spelunked just about every option I could in bios, changing bio-booter etc. incase it was a bios problem. Only I haven't changed any software in weeks since I got a new puppy and haven't really been downloading, installing or doing anything else that is even close to risky stuff or risky sites. 

 

I wasn't the one who built this computer though, I bought it second hand of a guy who'd barely touched it. Thing is this makes me a bit blind on how to error-test since I have no idea what any of all the cords to the cooler are for, so being unplugging and plugging etc. I'm not really sure what I'd be doing.

 

So, TLDR My cpu cooler is giving me a cpu_fan error in bios, fans are spinning fine but not cooling the connecter sitting on the cpu. Chillpaste, dust etc. are all fine. It HAS started normally three times but after two days of trying to make it work a fourth time I'd rather just try and fix the problem. No leaking or anything such that I can see. 

[Krehlmar]

Oh and it might just be something in software or bios, I'm not at all sure and none of the other topics seemed to adress my specific problem since most were about newly built, upgraded or hardware changed etc. whilst I've literally done nothing but playing eldenring and visiting normal dull sites in the last 8 weeks. Know this for a fact since that's when I got puppy and I barely have time for more than 1-3 hours of sitting 

[c-attack]

The H100i v2 gets it's pump and fan power from the motherboard fan header.  For most people this will be CPU_FAN.  In your BIOS make sure CPU FAN is set to "Full Speed", 'disabled', Maximum, or any other way your BIOS displays a 100% signal.  The pump needs 12v at all times.  As an extra measure, setting the header to PWM also guarantees it provides a constant 12v.  Motherboard fan headers can be unintentionally reset through BIOS updates or resets.  Also MB programs with fan controls may override any set BIOS commands.  Less than 12v might allow some fan action but the pump might not start.

 

If that checks out, then it's highly likely you have a developing hardware issue.  The CPU fan boot error is a warning that the MB did not detect the cooler on boot.  This can happen for a number of reasons from a failed or failing pump that does not send the return signal or something simple like a pinched tachometer wire on that lead.  Keep an eye on the CPU temperature if this happens again.  A real device or hardware problem including a pump start failure will cause your CPU temp to start rising dramatically.... 45..50..55..60..   80..85..90 all in about 20-30 seconds.  If the CPU temp is sitting at 30C in the BIOS, then the pump is most definitely running.  However, the difference may be academic.  Since the H100i v2 shares power and tach on the same line, either condition likely means replacing the cooler.

[Krehlmar]

Yeah the boot (the thing with chillpaste contact to cpu I take it?) is what's not getting cold so the cpu goes to 95c within a minute. It autp-shuts down now that I removed the boot to do more testing 

 

So when the error manifests it isn't viable, whilst during the three times there was no warning it worked fine. I'll doublecheck the cords etc. but if the pump works it aught to not give an error even if not connected to the boot right? Just so I can wriggle stuff around and test 

[c-attack]

This sounds more like a hardware issue.  Other than sub 12v start up levels, there is no reason the pump should randomly start or not and obviously its a highly undesirable characteristic.  One of these times it will stay off and its too erratic to keep managing like this.  The warranty is long, so check your purchase invoice and start a ticket with Corsair.  Otherwise, you need to start thinking about a replacement.  

[Krehlmar]

But how is it then that when it worked it worked for as long as I kept the computer running? Didn't shut it off for two weeks the third time for fear of it never working again, like it isn't now. 

 

Any speculation on what it could be, *if* it wasn't hardware? Thanks for your help so far 

[c-attack]

Improperly set CPU fan control (like a fan control curve assigned) does not create enough start up voltage.  My best guess is the pump motor has a developing issue and it is not starting sometimes when properly given the 12v.  This is why the issue is intermittent.  You can roll the dice and do a full shutdown, then power on again to try your luck again, but that is not a great way to live.  In general, I would expect the percentage of failed starts to increase as time goes on.  

[Corsair Notepad]

If you are still within the original 5 year warranty period from when you purchased the cooler I would recommend you reach out to our support team by opening a ticket at http://help.corsair.com

[Krehlmar]

On 5/28/2022 at 12:29 AM, c-attack said:

Improperly set CPU fan control (like a fan control curve assigned) does not create enough start up voltage.  My best guess is the pump motor has a developing issue and it is not starting sometimes when properly given the 12v.  This is why the issue is intermittent.  You can roll the dice and do a full shutdown, then power on again to try your luck again, but that is not a great way to live.  In general, I would expect the percentage of failed starts to increase as time goes on.  

Yeah I've been trying full no-static shutdowns during my testing but to no avail.

 

What's weird is how the pump hasn't leaked or anything, and I can feel it vibrating/pumping when I'm fiddling... It's just evidently not working with the heatstamp. 

 

Addendum; Ok so now I've checked every cable and I have no idea why it's not working since every component in its own seem to be fine, pump etc. but it just isn't. 
ADDENDUM2: Ok now I'm angry because after testing so much godamn stuff, just switching the 3tag cord to the motherboard plug with the secondary (removing a chassis fan and putting it in the cpu_fan plug that was giving the Corsair cpufan error but works fine with the chassisfan) removed the error. Gotta replace the chillpaste and rescrew a few things to see if that fixed it but at least some closure. If it still wont work after this I'll at least know why.

 

Weirdest thing tho since there's no dust, friction etc. where the motherboard plugs were (and it works on the chassis fan). I'll give a post scriptum later, if nothing else for my own closure. Thanks for the help

[Krehlmar]

Well even without the error the heatsink on the pump doesn't seem to entirely work. Even as the comp boots up normally cpu was at 90c+ so I tried removing it from the cpu and holding my fingers against it. It doesn't seem to be chilling the heatsink even if the pump-cables are vibrating as if it was working.