iMac i7-- click upon power down?

[TMRaven]

With the exception of some very, very minor yellowing and backlight bleeding, I've had a near flawless iMac, but one thing does seem odd/ concern me. Whenever I power down my computer (put to sleep, restart or shut down) something in the computer makes a clicking noise once. At first I thought it was the hdd, but it didn't seem to be coming from the exact same location or had the same sound as its usual faint humming.

When shutting down, the click happens halfway during the blue screen, so it seems as though the internals in the computer power down before the screen itself shuts off. Either way, am I the only one who this happens to, or is it just a regular thing that comes standard with the internals/mechanisms of the new i7 versions?

 

[WilliamG]

It is the hard drive. It's the head parking itself. Your hard drive is bang smack in the middle (well, upper middle), so you listen as you shut down/put to sleep your computer, and you'll hear the "THOCK!" sound.

http://www.ifixit.com/Teardown/iMac-Intel-27-Inch-Teardown/1236/2

My external drive (taken from inside the iMac) does this. But my SSD doesn't, of course.

 

[TMRaven]

Oh ok. For the longest time when I owned my G5 iMac, its hdd never made a clicking sound like that upon powerdown, but I suppose that clicking sound is something to be expected on certain models of hdds.

Hm, and I forgot it's in the middle. For some reason I thought it was right next to superdrive upon last reading the iFixit teardown.

 

[WilliamG]

Oh ok. For the longest time when I owned my G5 iMac, its hdd never made a clicking sound like that upon powerdown, but I suppose that clicking sound is something to be expected on certain models of hdds.

Hm, and I forgot it's in the middle. For some reason I thought it was right next to superdrive upon last reading the iFixit teardown.

Don't forget these hard drives don't all use the same heads, and I'm not sure if the heads are beefier for the bigger drives etc and create more noise when parking. I ripped my Seagate 1TB out of my iMac to replace it with an SSD. The Seagate is now in use as a Firewire 800 drive, and while it's not particularly noisy when in use, it's quite a loud blighter when it shuts down with that "CLICK!"

 

[Kabir8]

Oh ok. For the longest time when I owned my G5 iMac, its hdd never made a clicking sound like that upon powerdown, but I suppose that clicking sound is something to be expected on certain models of hdds.

Hm, and I forgot it's in the middle. For some reason I thought it was right next to superdrive upon last reading the iFixit teardown.

Everytime my G5 goes to sleep or shuts down, I hear a very distinct CLINK as I like to put it, and when I unplug my machine from the wall every night (you should too) I hear an additional CLICK and wind down of the Bus? Not sure what its called when you unplug from the wall...

It should be normal, unless it sounds grating or its really loud sometimes (like knocking) whereas its softer other times.