Harmonic vibration after replacing hard drive?

[chippy83]

I just replaced the original 640GB hard drive from my Early 2009 24" iMac. I installed a Seagate 1TB 7200 RPM drive. The install went well with only a broken microphone cable connector - whoops. The newer hard drive runs wonderfully however, I now have what I would refer to a harmonic vibration/resonance that I presume is coming from the hard drive. The vibration/resonance is consistently pulsing from nearly silent to quite loud. Has anybody else experienced this and what did you do to resolve the problem? Normally I would not worry about it but it seems to be the perfect vibration/resonance to gives me a headache .

Thank you in advance!

 

[AppleNewton]

Some drives vibrate due to the mechanics inside, I'd try reseating the drive. if you have external enclosure you can use to just power on the drive to see if it does it there as well you can isolate it. But seems like reseating it might help.