Dell Inspiron 15R 5521 Fan problem

Hello Dell,

I have a Dell Inspiron 15R 5521 laptop with an intel core i7-3517U processor. I recently had an issue with my audio jack and since the laptop was in warranty, I used dell's support service, where I was told that they had replaced the entire motherboard. That's when my problems began.

First of all, my Windows 7 installation couldn't boot or be repaired, so I did a fresh install of Windows. Now I am having this problem, where the fan runs at an extremely high speed, even though the cpu is under a small load and at low temperature, making the laptop extremely noisy.

I have the installed the latest version of the BIOS - A12. Running the diagnostic tests doesn't show any problems with the fan, so it is more likely to be a problem with the BIOS. I followed this guide http://www.dell.com/support/Article/us/en/19/428053/EN and also cleaned my vents, but that didn't change anything. I should also add the it is definitely not an overheating issue, as the laptop is noticeably not hot to the touch, and the cpu temperatures are all below 48 degrees C with a cpu usage of around 10%.

For the record I am running a Windows 7 Ultimate x64 with all updates and updated drivers. Core temperatures have been collected using HWMonitor. I haven't had a problem like this on my previous Windows 7 installation, but I have had similar experiences with my dual booted Ubuntu/ Arch Linux. Is this likely to be a hardware issue, or a software one, and if so are there any steps I can take to fix this?

Thank you in advance for any help with this question.