I get the same thing, but my front fan. Top fan was DOA and CM never got around to actually sending me the replacement. (even though there's a rad up there now)
I'd be interested in finding it out too, but it's not a big problem for me.
molex i was just testing the fans out as i only have psu case right now wating to get other parts end of week early next week. so ya psu to molex. but if i spin it by hand fast aswell it will make a noise for 1 second when it slows down only makes it when it slows down though the fans works perfectly fine it just makes a little whistle when it slows.
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