I got one of the new s12-500 supplies. I works fine expect for a weird rattle or chatter sound from the fan. Rattle sound is not rhythmic. Mainboard reports fan RPM as 1020. Has anyone else experienced this sound? Jim.

It is probably the ball bearings in the fan?

Mine used to do it a little, but after breaking it in a few weeks I haven't noticed it again. Mine too is running about 1000rpm, which appears to be its minimum speed.

J,

I agree with ilh. I don't have the psu but I have the fan and it is a bit rougher in sound than the D12SM-12 of the lower power S12's. However at 1000rpm motor and bearing noise tends to be less noticeable as air flow picks up. Hopefully it will get better. I've haven't run mine enough to really break it in. - FG

I listened to my fan again and its sounds pretty good with just a little bearing noise at low speeds, so chances are it will get better.

Maybe the fan guard is loose or the psu case is transmitting some vibration to the case.

If it were bearing noise would it not be the same sound in a rhythmic pattern or a constant sound. This rattle happens every few seconds with no apparent pattern. It is not case vibration or a loose fan grill. Jim.

J,

Bearing noise can be a constant rumble at low speeds that seems to dissappear as air flow noise increases, covering up motor and bearing noise. You can still usually hear some motor noise. In a nexus it is a low non intrusive sound and in other fans it can be a higher pitched sound. This becomes the characteristic sound of the fan. Sometimes, bearing noise is noticeable when you tilt it from a vertical or horizontal plane.

At 1000rpm, in most fans I've listened to, it is hard to hear much bearing noise, especially inside the case. I have noticed on a pretty good fan a resonance at a certain frequency, but that noise is closer to a constant whine that disappears quickly as the speed changes.

It sounds like the noise you describe is very annoying and I don't think that is normal. So if its not a loose wire or something that comes in contact with the blades, it should be quiet fan without the kind of noise that you describe. Since you can't take it apart without loosing the waranty I would call seasonic and see if they can send you a replacement or the dealer unless it was newegg in which case they can't really help you other that to exhange it and charge a restocking fee. - FG