Computer Power Supplies

My computer power supply failed. For the past year or so my computer would occasionally turn itself off (when I'm playing Civilization 4 only if I was running a lot of applications at the same time, or hadn't rebooted for a long time - eg it was during high RAM/CPU usage). To fix it, I'd have to unplug the power cord and plug it back it (the reset/power button didn't work).

One day it turned off, and didn't turn back on.

I did some web-research (my computer is a Compaq S5000J, AMD 2600+, 1GB PC2100 RAM) and that gave me the bad impression that it was my motherboard so I ordered another one. After taking it out and putting all my components on the new motherboard - it didn't work. So I replaced the powersupply and it worked fine.

I suspect that either my power supply failed on its own (apparently they are on of the most likely components to fail, and my computer was super-dusty), or I might have been overloading it. Really though I'm only running one hard-drive, a floppy, a DVD (off most of the time), 1 GB RAM (this is the limit) and a cheap GE FX5500 video card. Based on my research the video card probably uses 20 watts of power. The power supply is 250 watts. Blaming the video card makes sense if you consider the fact that it is only intensely used for Civilization 4.

To call it safe, I'm going to replace it with a 300 watt one. Also power supplies are typically more energy efficient when they aren't running at maximum capacity. Apparently power supplies are typically only 75% efficient which is a bit of scandal (because they could achieve 80-95% efficiency), particularly with the newest computers that are using 350 or even 400 watts.

While I was getting my house in order, I reinstalled XP on a new hard drive because XP had a "takes 20 minutes to load Internet Explorer (and a series of XP system apps)" bug that was extremely annoying. The new hard drive and/or power supply, made me call Microsoft, because my XP key wasn't working for the reinstall. Fortunately, other than trying to trick me by asking "How many computers are you installing this on?", they were helpful and gave me a code that worked.

Hmm, my previous computer (AMD K6-2 550mhz, win98) has even bigger issues with turning itself off. The weird thing is that it takes time to warm up in cold weather (50 degrees is bad). I wonder if that is a power-supply issue? It's had it from the beginning.