Which malfunctions cause old computers to slow down and crash?

I've had a few computers of my own break after a few years of use, and I've seen computers owned by friends and family do the same thing. They either slow down (even running the original software they shipped with) or crash more often (kernel panic/BSOD, freezing, etc). All computers eventually fail, and not always in easily explainable ways.

For example, my first computer was a MacBook Pro. After about 3 and a half years of use, it started to freeze a few times a week, then reliably every day. OS X would stop responding; my mouse moved, but absolutely nothing responded. It ended up lasting more than four years, but I was in the habit of saving my work every time I paused in typing, and kept rigorous backups.

I've also seen old family computers running early versions of Windows completely freeze (no mouse movement) just after completing startup. And I've seen a 4 year old 12" PowerBook G4 run like molasses even after having been wiped and reset to factory settings and OS.

What causes this? Do the electronic components break down over time?

Solution 1:

The environment has an effect on your computer.

Temperature changes make electronic components expand and contract, if they do that a lot of times eventually connections will get damaged and even break. This results in different resistance which reroutes the power and causes components to behave in an unexpected different way.

This is why in some data centers whole server rooms are cooled with gas to keep the temperature at a constant level, besides keeping the servers from overheating this also keeps the hardware lifetime.

Humidity changes are also not very good for electronics, this can lead into different conductivity; or in the case of condensation, it could even short circuit an electronic circuit.

This is also why they very tightly seal electronic circuits on a ship, even though the rain and sea can't reach the electronic circuits. That way, the circuits don't suddenly start to malfunction when they are in the middle of the sea. Better to be safe, than to be sorry...

There are other factors like (direct) mechanical or magnetic damage, as the environment is not the only cause of damage. An example is a hard drive running out of its lifetime or the computer being placed near magnetic materials. But components like hard disks are known to not keep on for more than a few years; while not mentioned explicitly when sold, one should keep track of its state as a good habit.

Solution 2:

Unmentioned in the existing good answers are electrolytic capacitors, which vary widely in quality and life-time and whose failure can bollox the performance of your power supply or the time constants of connections between components.

These little guys have been blamed for a number of "lemon" laptop models and high failure rates in other equipment over the years.

Solution 3:

The vast majority of problems you see are related to either heat or mechanical failure.

Both can because by the build of of dust, which blocks fans airflow and so on. This causes components become warmer then they should.

Another less common possibility is bad power. What you get from your AC outlet is not always a nice clean 120V @ 60HZ (or whatever is appropriate for your location). A computer power supply can tolerate some variability, but not always.

There can be lots of problems with software, but they can almost always be solved by a re-install. If a computer is 'locking up' with no other apparent symptoms it would be a good idea to boot of a livecd and run memtest86 and similar diagnostics.

Keeping your your computer free of dust, running it on a line-interactive UPS, and making sure it doesn't get get overly warm will lower the chance of hardware failure.

Laptops/portable systems are a special case. In is almost certain that they will be dropped or have something spilled on them or so on. Even the most cautious person will almost certainly drop it, or bang it against something. The damage of this kind always seems to be cumulative. A small drop, may not seem to hurt the system today, but that combined with heat, and be moved around and so on will almost certainly cause something to fail eventually.

Solution 4:

I know that the question already has an answer marked as correct but, I would still like to throw in my own thoughts.

As far as the computers running slower, could it be possible you have gotten used to newer technology? I always feel like an older product has something seriously wrong with it when it goes slower compared to its newer counterpart. Our expectations have grown since their, era. Could it be that your expectations are slightly unrealisticly high?

Just a thought, depending on your circumstances (and most of them, such as the constant freezing) probably have nothing to do it.

Solution 5:

There are some possibilities.

Due to thermic stress on the parts, like turning the computer on and off, putting heavy usage on certain parts for short intervals etc. you might slowly damage components. Tiny cracks will build which can later damage electric connections.

They probably will make it easier for oxydation or other reactions (plastic will lose its softeners over time and crack) to get to critical parts. Pure Silicium is very prone to oxidation as far as I heard.

Another possibility is mechanical stress inside harddrives or optical drives and maybe even non stable electric input through the power supply unit.

All those are more or less speculative, but googles paper on harddrives is a good read on the thermal and mechanical topic.