Computer startup problem? Verify that the power button works properly
It’s something we all fear, but it has probably happened to many of us at one point or another. We turn on a computer, and instead of coming to life, nothing happens: the computer appears completely dead. Although the cause of the problem is usually a faulty power supply, sometimes the power button may not work properly. Before investing in a new power supply, you can easily verify if this is the case.
First you need to open the computer case, this is normally accomplished by removing the left panel of the computer (viewed from the front), this usually involves simply removing two screws from the back of the case. After removing the panel, lay the computer on its side on a flat surface. You need to look carefully for a series of thin cables that run from the front of the case to the motherboard of the computer. Cables are normally in pairs of different colors and each pair leads to 2 small pins on the motherboard; On the motherboard (and in the motherboard manual) you will find text that indicates what each pair of cables does. You will have one pair for the internal speaker, one pair for the reset button, one pair for the power switch, and one pair for the power light.
The wires we are interested in are the ones marked as power switch which are often shown as PWR-BTN or something similar. Unplug these cables from the motherboard by gently pulling on the connector. Next, you will need a small flat-head screwdriver that can be used to bridge the gap between the pins on the motherboard where the cables were connected. The computer must be plugged in and if there is a switch on the power supply on the back of the case, it must also be on. If the computer starts up when you make a connection between the two pins with a screwdriver, then you know that your problem is a bad power button or a bad connection between the power button and the motherboard. Be careful not to touch anything with the screwdriver other than these pins.
If the computer still won’t turn on, the power supply is most likely causing the problem.