The exact nature of the sound is like the one made by phones with dials (remember those?) when small numbers like 1,2 and 3 are dialed. The noise is audible only when there is good amount of silence, like post 10pm, and seems to happen when idle.
The laptop works as though there is no problem. The only strange behavior I have noticed is it had shut down overnight a couple of times (usually it sleeps and goes to post sleep, hibernate I guess, but won't shut down).
This is my development laptop and is five years old. It is a Dell Inspiron 15 R with Windows 7 64bit Home Premium. Lately I have been doing web front end development actively which involves lot of saving .js files and refreshing .html files in the browser(Firefox 42). I suspect that it is still better than Visual Studio building C++ files wrt wear and tear on the hard drive when I could actually hear it churn. Also, I treat my laptop with respect, so won't hold it in odd positions etc. It is basically a laptop on a desk.
Anyone with similar experience? Is the hard disk failing or is it harmless?
