Two and a half years ago I replaced my fairly conventional desktop PC with an Intel NUC, measuring about 4 inches square.
It has performed well - better than I had expected - thanks to its quad core Intel Core i5 processor running at 2.3 GHz, along with plenty of fast memory and a Solid State Disc (SSD). The result is a PC which is more than capable of carrying out the audio-video tasks I throw at it, plus anything else I might do while sitting at a desk. And it runs virtually silently, like laptops do.
Until about 3 months ago. The NUC usually runs quietly but I noticed that the relatively noisy fan was coming on more and more and eventually it was on continuously. Apart from the noise, I was aware that the fan indicated that the PC was getting hot.
I updated the drivers and fiddled with the BIOS settings but this only made the fan spin faster - and more noisily.
Worse, the PC started shutting down because of over-heating, resulting in loss of work and general annoyance. Clearly, this needed to be sorted. Fortunately, a bit of Googling led to me to the solution.
Inside this tiny PC there is virtually no spare space. The fan is shoe-horned in and, put simply, after a while it gets blocked with fluff. The disassembly instructions were simple and involved removing four screws, unclipping the memory and the SSD, and then disconnecting the fan. And yes, it was full of fluff. Careful removal with tweezers and an air duster resulted in an immediate return to the silent running I remembered.
For good measure I installed a small program, CoreTemp, which monitors the CPU temperature. Before de-fluffing, it was running at over 80 degrees; after de-fluffing, it runs at about 30 to 40 degrees.
Success! I’ve made a diary reminder to clean the fan each year.