[CM ATCS 840] Vibration-humming with both top fans on?

[pete2s]

I'm having a problem with my new ATCS 840 case and I'm wondering if others have this problem.

With both top fans on, I hear a low, humming vibration that goes in and out. It starts off weak for a second, becomes louder for a second, and then fades after another second. The vibration-humming repeats ad nauseam.

Theorizing that this was the fans vibration sine waves overlapping, I disconnected one top fan. The noise stopped. I then tried disconnecting just the other top fan and the noise stopped as well. The source of the vibrations is definitely the two fans throwing out different waves of vibration. This is probably normal and expected unless you had two fans that were exactly the same in every sense.

With my hand, I feel the vibrations through the left side of the case (the side you open to install components). If I push this side in with my hand so that it bows in rather than out, the noise is barely perceivable. If I remove the left side, the noise is gone--even with both tops fans powered.

I've tried many solutions to no avail. I reinstalled the top fans, making sure to evenly tighten the screws. I've tried tightening the screws and I've tried keeping them loose on both the fans and side panel. I've even tried keeping it running for a day in the hopes that the fan vibrations would eventually sync. Nothing has worked.

I'm beginning to think that all the reviews made my expectations too high and that this is normal; however, the case is almost silent with the side panel off. For owners of the ATCS 840, do you hear these vibrations?

[ncsa]

I have recently got ones of these cases up and running and do not experience any of these symptoms... are you running them off a fan controller or other similar header where maybe they are not getting enough 12v?

Mine are direct connect to the PSU and run slightly fast due to the 12v rail of this PSU running a little higher ....

[pete2s]

I am not connected to a fan controller. I have one cord coming out of the PSU which connects to the top 2 fans and the front fan. Should I have the fans on seperate cords?

I'm getting the feeling that the issues are 1) an uneven fan and 2) loose side panel. The side panel often can vibrate to the point of rattling. I'm not sure if I should RMA the entire case to Newegg, or try to get new top fans and panels from Cooler Master.

[Zenphic]

It might be a loose side panel, and the vibration might be caused by air turbulence or the vibration of case fans. I'd suggest buying some rubber or silicone standoffs for fans to see if it helps.

[boredgunner]

It might be a loose side panel, and the vibration might be caused by air turbulence or the vibration of case fans. I'd suggest buying some rubber or silicone standoffs for fans to see if it helps.

Maybe after he fixes the issue because this is not normal. I have the case and there are no vibrations.

I would remove the fans and put them back on, and secure the side panels better if you can.

[EsaT]

Yep, some interaction/resonance between fans.
Fan speed isn't any rock solid constant but can have slight cyclic variation so at certain point of cycle vibration of fans probably hits to same phase.

You could also try adding bitumen mat to side panel.

[pete2s]

The problem has been resolved.

The source of the problem was the back top fan. I received a replacement the same week I did a part request. The fan is the same model but different version and has no issues.

The rattling and excessive noise as a result of the pulsating vibrations were from a loose side panel. I tightened the "teeth" on the panel by using pliers. The side panel now fits securely and does not rattle.

I also tightened the teeth on two other computer cases that I did not consider noisy and noticed a reduction in vibration and noise. A good recommendation I received from CM tech support is to always tighten side panel teeth.

[Sheira]

Hello.

I have exactly the same problem with my ATCS 840. While it is hardly noticeable during the day, in the night i can literally feel the vibrations while i am laying on the bed.

I tried to remove top-back fan and it indeed seems to be a source of this noise. I am gonna play with it, swap the both top fans, tigthten the screws etc., but if that wont work, what should i do?

You said, you had your fan replaced. Who you contacted with this?

Cheers.

EDIT: what i did so far, i swapped 2 top fans - the vibration doesnt seem to be eliminated.

[allup]

I the fan in the top has a vibration and is pulsating a noise. Try making the top fan-holder bracket so it does not move, even a little bit. My top fan was getting a bit of a rattle, it was a "new" fan. The bracket it was in was not tight so i put a bit of filler that i use on things between the fan holder and the case, issue solved, and yes the side panel teeth is another way to reduce overall vibration in the click lock cases..

Hope that helps