Click Click Click

Today, I noticed a clicking noise coming from my office Fujitsu notebook. It has been with me for 6 years now since 2009. I hope the clicking noise is not a symptom of something serious to come. Spooked by the clicking noise, I started backing up all my data. A colleague thought it may be the fan making the clicking noise as it came from the left side of the notebook. I really hope so. 
Any "new" replacement notebook from my workplace are recycled notebooks from projects that have been closed and they are likely to be at least 3-5 years old too. :( Not any newer or better. Sigh.