The only problem I find is lack of maintenance. I have replaced bad
power supply fans. I have found systems with stuck fans and so full of
dirt that even if the fan was working there would be inadequate cooling.
The dust and dirt acts like insulation, where you don't want it.
The components do fail if overheated. A computer should be opened up and
blown out once a year especially the processor heat sink and power
supply box. Bad or noisy fans should be lubricated or replaced.
Maintenance will never happen though, people pay their boxes no mind
until there is a problem.
Opinions vary on this. Personally I don't see much point in opening
up machines for this kind of regular maintenance. I alot of the
rationale for dusting machines is of the form "Look! Isn't that
dusty! All that dust must be doing some kind of harm..." without any
rational thought going into whether the dust is really causing a
problem or not.
It takes a _lot_ of dust to have any significant effect. A thin
layer, just enough to make things look a bit grubby, does no harm
whatsoever. Look at where the dust gathers - it doesn't gather at
random, in the main it gathers where there is poor airflow anyway
because cooling isn't such a big deal - between the expansion slot
sockets for instance. The dust you inevitably get on fans doesn't
usually amount to very much - it gets blown away when it gets thicker
than the boundary layer.
Yes, you do sometimes see PSUs in particular absolutely full of dust,
but these tend to be on older machines and even then are the exception
rather than the rule. Over the weekend I opened up a 12 year old
sparc I still have in daily use and the PSU was certainly full of
dust, but I didn't bother cleaning it out and it isn't causing a
problem. There should be sufficient margin built in that even a lot
of dust like in this instance doesn't cause a problem. If that isn't
the case you have problems long before you consider dust.
You have to consider the time and expense of performing the
maintenance, which in a commercial setting is not insignificant,
against the chances of a computer failing as a result of not beign
dusted. It isn't just an enginner opening up the case and squirting
an airduster about - the engineer has to be on site, and it is usually
demanded that the user completely clears their desk before the
engineer even looks at a machine. Additionally there is always the
risk of inadvertently damaging something or simply wearing things out
- machine threads in aluminium cases come to mind immediately here.
There always seems to be a finite number of times you can screw/
unscrew them before they are completely shot.
So yes, in extreme cases dust build up can cause problems, but those
cases are few and far between. On balance I don't think it is worth
the hassle. If you want a cleaner computer don't smoke around your
machines - that's a good source of dust and airborne tar is one of the
best things going for clogging up machines.
