Random Shutdowns, Won't Even Startup Now

There are 2 common causes for that.

1. The old bad cap issue. Read http://news.com.com/PCs+plagued+by+bad+capacitors/2100-1041_3-5942647.html

2. A just big enough supply. I won't go into great detail but as the voltage sags, the current goes up. So my lesson was to always fit a monster of a supply. I see 500W listed but I wonder if the machine's mainboard has issue #1 or has many many power hungry cards.

Bob

I've seen problems like this before. If you have a fluke and the proper information, test the out some of the outputs of your power supply, that's probably the problem.

A downstream problem may exist too. The components on your motherboard that are sticking up are the most likely to fry. You might want to give a close inspection to alot of those. A simple resistor or capacitor burnout will appear discolored most of the time and is very easy and cheap to fix. But since you're computer didn't just stop working all at once, that's probably not it since the components are not very old.

You can buy a power supply with close to the same, but slightly higher, tolerances and price. Install it and see if it works. If it doesn't work, take it back and just act dumb, saying it doesn't work. Or you could take the CPU into a computer shop and have them look at the whole thing, or the less expensive option is just take in the motherboard.

The brown discoloration you see on the pins represents high current flow, not a high-resistance connection. So you may need to replace that cable as well as the connections. It happens when one of the voltage or current regulators fail in a power supply, which is not that uncommon. It also happens over a period of time. Sometimes it's a day, a month, or just all at once. But usually around a week.

If you're computer is not showing you anything whatsoever, just replace the power supply. It's not too expensive. You would have noticed other problems way before it went dead if components were starting to fail.

If it happens to be a single-component failure on your motherboard, the casing of the component will be crunchy with a soft squeeze and if it's not all black or brown, it will look burnt or discolored. All you would need to do is buy a new component of the same rating and solder the new one in its place.

If it's a silicon component embedded in the motherboard, there's not anything you can do but replace the motherboard. You can remove the processor and RAM and use it in the new motherboard without any problems if they match the specs of the new one.

As I said, it's most likely your power supply though.

Hope this helps.