New laptop fan runs continuously (NOT a heat or dust issue)

[NonyaBizness]

I've replaced the fan on my laptop (HP Pavilion DV7-6b54ea) as the bearings were grinding on my old fan, but my new fan now runs constantly despite low temperature (as low as 35 degrees) and low CPU usage (0~2%). To be clear, this is NOT a temperature issue or high CPU/GPU usage, nor is it a dust issue as I completely cleaned the radiators, air intakes and motherboard when I installed the fan, and the heat pipes and other components are in good condition.

I have disabled the Fan Always On setting in BIOS, and I have set the System Cooling Policy in Advanced Power Settings to Passive. I also checked for any relevant updates or drivers and none were available. Online resources suggest restarting the laptop, opening BIOS and setting the fan's minimum speed by selecting "Power" then "Thermal", but my BIOS (version f.02, baseboard 1800) does not have those options. I've downloaded a BIOS update (sp59755.exe) but I'm unsure whether to install it. I upgraded to Windows 10 years ago, but the only option at hp.support.com for my laptop was for Windows 7, which is what my laptop was running when I bought it, so I'm unsure whether the BIOS update is suitable.

I thought I may have inadvertently bought a single-speed fan rather than variable-speed fan, so I contacted the vendor for more information and they confirmed that it is a variable-speed fan. I suppose it's possible that I haven't installed it correctly, although it is working, just not as intended. Other than the fan running continually at a constant speed there are no other issues currently affecting my laptop.

Please could somebody advise me as to what to do next? Thank you in advance.

[WAWood]

@NonyaBizness 

The BIOS update will not run as the HP updates are OS-version specific and one released for Windows 7 will not run under Windows 10.

I've replaced fans on laptops and desktops and it has always been a simple swap; so, I see no reason why the new fan should not be behaving like the old fan.

Was the old one running all the time and the noise was annoying?

Other threads here for this issue have received the response to replace the thermal compound on the CPU with new compound. Since you know how to replace the fan, you could probably do that on your own, as well.  Myself, I would advise against this unless you have done this before as applying thermal paste can be a tricky process to get right -- and if you get it wrong, you could burn out the processor.

[NonyaBizness]

Thank you for the reply. First of all, you're wrong about the BIOS update. Having run out of ideas I updated it a few hours ago (from f.02 to f.1b) without any issues, but it did not provide any more options like "Power" or "Thermal".

I'm a bit surprised that more-or-less swapping like for like has caused this issue. However, to install the new fan I had to get under the motherboard to reach some tiny screws from the underside, and to do that I had to unplug everything, including the little battery. Could that have caused it to 'forget' some settings?

In answer to your question, the previous fan did not run constantly. It only kicked in when the processor warmed up, at which point it made a loud grinding noise. Cleaning out any trapped dust made little difference, which is why I opted to replace it.

I guess I should repeat that this is DEFINITELY NOT an overheating issue. There never was a problem with the temperature, and with the new fan running constantly the temperature stays around 45 degrees. It's blowing out cold air.

I've had CoreTemp installed for years and can see the temperature on my taskbar. Yesterday I also installed SpeedFan, learned how to use it and configured it to respond to the temperature accordingly. However, it only controls two readings, both labelled "GPU Fan", and the CPU fan is still fixed at 3825 RPM. The good news is that, with SpeedFan, I've confirmed that all components are in good working order, the various temperature sensors (CPU, both GPUs, motherboard and HDD) are all working correctly, the fan tachometer is working, all the voltages look fine and wotnot.

If I could get SpeedFan (or the computer itself) to recognize that there is only one fan which cools the entire laptop I could have total control. Unfortunately, having familiarized myself with every setting available under the "Advanced" options tab, I can see no way to do that.

[NonyaBizness]

@WAWood  I'd really appreciate it if you could help me to resolve this issue. Perhaps there's another HP support service that I could contact? Nothing I have tried so far has worked. I even tried emailing the creator of SpeedFan but did not receive a reply. I don't know what else to try.