If you are someone who uses your computer for extended periods of time, the worst thing is when your computer experiences power failure. If this consistently happens, the first thing you should do is check your power supply. Making a power supply tester is a great way to determine whether it is indeed your power supply that is failing you.
Strip off the black, green and red wires at both ends using your wire stripper.
Wrap your black wire to the LED. You will want to connect it to the shorter lead coming out from the LED.
Connect your red wire to the longer lead that is connected to the LED. You will do this by wrapping the wire around the metal of the lead. If you prefer, both the black and red wires can be soldered onto the leads.
Cut the black wire you connected to the LED in half. Strip all ends of the black wire.
Join the green wire to where the black wire is connected to the LED. Now the green and black wire will both be connected to the same side of the LED. Also connect the black wire that you have cut off to the short side of the LED lead.
Connect your wires to your power supply. The green wire will connect to the pin that has a green wire leading from it. The black wires will connect to the pins that have black wires coming from them. The red wire will connect to the pin that has either a red, orange or perhaps yellow pin leading from it.
Switch on your power supply.
Observe your LED. If it lights up, the power supply is in working order and you do not need to replace it. If the LED fails to light up, the power supply is not working and will need to be replaced.
- power supply cable image by Christopher Meder from Fotolia.com