You know how they say that a picture is worth a thousand words. Well, here are three pictures that speak volumes towards keeping your machine clean.
Beneath the fan, the CPU's heatsink was covered by a blanket of dust. This caused the CPU to run hotter than normal because it wasn't able to cool properly. The motherboard sensed that the CPU was hot, so it told the fan to spin faster. The faster spinning fan was much louder than normal, which is what prompted the customer to bring the machine in for service in the first place.
The memory module was coated with a layer of dust as well, but surprisingly it worked fine once it was cleaned up with some compressed air and reseated. In the past we have seen heavily coated memory modules throw errors after being run like this for a while. Presumably due to the heat from around the CPU or maybe static charges involving the dust somehow.
In the end though, this machine ran much quieter and cooler once it was properly cleaned up. Of course while it was in, it was also scanned for adware, spyware, viruses & trojans just to be sure - and as usual, a handful of common items were located and removed.
