Obsidian 900D stock fans make buzzing noise

Hi Corsair!

Earlier today I was pleased to see that my Obsidian 900D had arrived, and I am very happy with the case except for one not-so-small thing.

All four of the stock fans make this horrendous sort of buzzing/grinding/clicking noise when they're powered on. It's only when they're recieving power, and seems unrelated to the speed at which they're spinning. To test this, I tried two things. 1) I manually slowed the fans using my finger on the center of the fan. A lower RPM simply resulted in a slightly lower delay between the "clicks". 2) I used a resistor to bring the voltage down to 7V. This resulted in softer "clicks", but had no other effect. Additionally, I've tried two seperate power supplies.

I've made two videos to demonstrate the issue. (Both videos are of the 3 120mm fans in the front of the case, but the 140mm in the rear makes the same noise. Note that there is no other mechanical device in the case that could make the noise.)

While I realize stock fans generally aren't the quietest, I was expecting better for the price I paid for this case, and I know that fans aren't supposed to buzz or click.

Really, I just wanted to check that this was indeed not normal, and a valid reason for requesting that they be replaced.

Indeed, I have tried each one individually, and I realize the chances that each fan is off. While one or two is worse than the other, they all produce that grinding noise.

Due to the high cost of shippping internationally to your return center (which last I had to RMA was, if I recall correctly, in the Netherlands), I'll first see if I can get the fans exchanged from where I bought it.

Thank you for your time and help, Greybeard, and I will return should I require further assistance.