The right tool, combined with the right knowledge, will enable you, the not-so-computer-expert, to fix just about any problem you might have.
Here you'll find lists and reviews of hardware testing devices, information on buying the right computer screwdriver toolkit, tutorials on testing important parts of your computer, and much more.
How Do I Test the Power Supply in My Computer?
You can test a power supply with a "power supply tester" or you can do it manually. Either method is OK and I have complete tutorials on both.
How To Manually Test a Power Supply With a Multimeter
One way to test a power supply is with a multimeter. It's not easy, but it's very doable when you follow this helpful guide to the letter.
How To Test a Power Supply Using a Power Supply Tester
Testing a PSU with a power supply tester is an easy, and completely safe, way to check to see if a power supply is working or not.
How To Test for Power Using "The Lamp Test"
A tutorial on performing a "lamp test," an easy way to verify that power to an outlet is good.
My review of the NewerTech NWTU2NVSPATA UPS USB 2.0 universal drive adapter, a device you can use to connect a hard drive to another computer, which can be very handy when solving many kinds of major computer problems.