loud HD click sound when picking up laptop while on...

Thought I'd post this incase other's might be wondering what the CLICK sound is coming from in their late model macbook pros. My MBP17 was purchased back in May of 09.

When the laptop is on and I pick it up to move it I would often hear a loud CLICK sound coming from the HD. It had me freaked out that something was loose or that the heads were scratching the platters.

I just came across an article explaining what this noise has been. It is the sound of the read/write heads parking because of the "Sudden Motion Sensor" built into the laptop. It senses the rapid movement when I pick up the laptop and then it parks the heads to prevent scratching the platters... that is the click sound of the heads parking.

The sensor is a tri-axis accelerometer that detects sudden changes in "position and accelerated movement".

Anyways, I tested this to see if it was the "sudden motion sensor" parking the heads:
- first I confirmed that the sound would still occur when picking up the laptop and tilting it quickly while still on
- then I checked the sensor's settings to see if it was really on by running a command I found in the linked article.
- then I turned off the sensor (that command is also in the article).
- then I tested by picking up the laptop again and tilting it quickly...

no more CLICK

I enabled the sensor again because it is better to have it enabled than to risk scratching a platter if I drop the laptop. I'm just happy to have found the source of the CLICK and to know it wasn't a faulty HDD.

Here is the article:

http://reviews.cnet.com/8301-13727_7-10408737-263.html

 

Yeah... Cool?

 

Yeah, I thought it was pretty cool and interesting. But was actually more of a relief to simply know the click was not anything bad

I also enjoy any chance I can get to use the Terminal window and try my hand at new commands from the command line.

I find myself going through the /usr/bin directory alot and using the "man" command to try and educate myself about all of the commands and scripts found in there. Just have to remember to be careful what I play with in there. I don't want to do something stupid like an "rm -vr *" and wipeout my entire file system. ha

Ben

 

There are a number of threads around about the sudden motion sensor already.

As for running random commands and scripts, personally I'd rather research what they do first instead of running them and then worrying later that something got screwed up.

 

Hi Khris,

I am sorry, I did do a search first and then I searched again just to be certain I wasn't duplicating other threads/posts. I began searching on "SMS" but that just gave me alot of posts about text messageing, lol... then I ran a search for "Sudden Motion Sensor" but the most recent I could find was from 2008 and those did not really describe what SMS is or about what it does with the parking of the read/write heads. It is also very possible that my search skillz are lacking. LOL I do apologize especially if this is already common knowledge to the apple community here or if recently discussed. It was a revelation to me and I thought it would be beneficial for me to share what I learned.

I also should clarify... I do not actually run random commands but I do run man pages on them to learn what they do.

Ben

 

You just need to use the search properly. I searched for "Apple Macbook Motion Sensor Hard drive" and came up with this, http://forum.notebookreview.com/showthread.php?p=5413984

 

haha my search skills are lame. thanks - Ben

edit: if MOD would delete this thread please. [embarrassed]