I recently installed a couple of new packages on my trusty HP ML115 G5 internet facing Debian server. This server is normally virtually silent, only occasionally getting louder when under increased load (oh, apart from when it is rebooted when it sounds like a Boeing 747 taking off for 20 seconds or so as the fan is run at full speed!) However, after this recent update I noticed that the fan noise was significantly louder than normal even at idle. I couldn’t believe that installing these new packages had any link with the increased noise but I didn’t have time to investigate further until a couple of days later…

After eventually proving that the increased fan noise was not down to increased load on the CPU I decided to pop open the side panel to take a look… and it was then that I noticed a ball of fluff and a fair amount of dust on the CPU heatsink and fan. The fan was running smoothly, but faster and noisier than usual. So I gave it a quick blast of air, the dust and fluff was removed and within a few seconds the fan noise reduced to almost silent again!

After so many years living and working with computers I can’t believe I didn’t check the stupidly obvious. So, from now on, whatever the IT problem, I’m going to check for dust and fluff first!