My machine locked up sometime overnight, and when I rebooted the memory test
took forever. I thought it had frozen at that point, since it wouldn’t even let
me into the BIOS, but eventually did boot into Windows. Prior to this I had run
a memory test program, and it had, in fact, shown errors, but those went away
after I re-seated the memory cards on my motherboard. Someone mentioned that
the power supply might be the cause, is that possible?
Most folks think a power supply failure will be catastrophic … bright
lights, flashes and smoke followed by no power; or just the sudden “no power”
part without all the excitement.
The reality is often more mundane, and, for lack of a better word, at times
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Power supplies can fail in a number of ways, and the catastrophic failures I
mention are certainly possible.
What happens more frequently, though, is that the power supply slowly begins to not
be able to provide enough power to run the machine. That can happen for
a number of reasons, the most common being adding more hardware to the machine
that causes the entire machine to require more power than the supply can
Power supplies can also fail gradually over time. Perhaps it’ll slowly drop
the voltage it’s supplying; the expected 12 volt output will start dropping to
something less than that. How much less gets worse and worse over time until
something finally gives.
What might fail actually depends on the tolerance of the various components
in your computer. Many are quite tolerant and will run with an amazingly
off-spec voltage, and others not so much. Sooner or later the component with
the least tolerance may start to show errors, which themselves could be
anything from incremental hiccups and crashes to a sudden catastrophic
call in a technician …”
It appears that it’s often the memory that shows the symptoms first (though
not always). Reseating the memory could have temporarily improved the
connection allowing the memory to get just enough more to be ok for a while,
but if the power supply continues to get worse, that’s not a permanent fix.
So if it could be the power supply, but it could be the memory, or it could
be something else, how’s a person to know what to do?
When it happened to me some time ago, I guessed. I replaced the power supply
in a machine that started misbehaving, and sure enough it began to work
reliably again. My guess was an educated one, though, as I had added hardware
to the machine, increasing its power requirements, so when I replaced the
power supply I made sure to replace it with one with a higher wattage
If you’re not comfortable guessing, it might be time to call in a technician
who can actually diagnose where the problem really is. Determining with any
certainly exactly what’s contributing to broken behavior is not easy. In fact,
many times even the technicians will simply swap parts until things start
working. In effect they, too, are guessing.