Noise from psu fan under low loads

[snusprilla]

I recently bought an Omen 25L desktop (couldn't find the specific model) with a Cooler Master 500w psu. I believe it's custom made. 

Ever since I first booted up the pc there has been a noise coming from the psu fan. The fan starts spinning up and 5 seconds later it stops and  there is this grinding noise. I've tried checking for stuck cables and tightening any screws but the noise is still there. It only happens under low loads such as browsing the web. It's really annoying and I've tried searching for answers but found nothing of any help. I've never heard anything like this before but other than the annoying sound the psu fan works fine under heavy loads with no noise.  

Any help regarding this is appreciated.

[Photoray002]

@snusprilla 

There should not be any grinding noise coming from the PSU.

You would do best to contact Support for a warranty claim. They will most likely replace the PSU if they see fit.

Contact HP Worldwide | HP® Official Site

or

https://support.hp.com/se-sv/contact/desktops