Although not the worst problem that can happen to a computer (A completely corrupt or inaccessible hard drive can be, from indirect costs), it can still be the most expensive. In most cases, if the problem lies with the motherboard, the cost of the motherboard can exceed the cost of the laptop or desktop PC. The good news is, in most cases, power related issues are not caused by the failure of the motherboard. Here are the most common causes of a no power problem:
Bad AC Adapter or Power Cord
70% of all computer related issues are caused by a loose or bad cable. When troubleshooting a no power issue, always try a different AC adapter or power cord first. This is the most common cause for no power. Thankfully, this is also the cheapest fix. Power cords can range from $ 5 to $ 15, depending on where you get it from. AC adapters for laptops tend to run a little more in price, anywhere from $ 15 to $ 80.
Loose DC Jack on Laptops
A DC Jack is the port where you plug the AC adapter into on a laptop. The pin in the middle is what transfers the power from the AC adapter to the laptop. The pin is held in place on the motherboard by what is known as solder. Solder is a metal that heats up at much lower temperatures than normal metals. This allows a DC jack to be replaced at a much lower cost. All you need is a soldering iron and some flux solder. Although a laptop DC jack only runs between $ 3 and $ 5, the labor cost to replace is high. Try taking a pen tip or small screw driver and see if the middle pin wiggles when you apply a small amount of pressure. It is highly recommended you take it to a professional computer repair specialist if the DC jack is loose, unless you are experienced in soldering.
Bad Power Supply on Desktops
This is another very common problem on desks. Power supplies a very sensitive to power surges. If your computer is not plugged into a surge protection strip and directly in a wall outlet, then this is the most likely cause. A bad power supply can also be caused by overloading its capabilities. Check the WATT capacity of the power supply and make sure your computer does not require more than 90% of the power supply capacity. The extra 10% will help the power supply last much longer. If you press the power button and the computer immediately turns off, an overloaded power supply is the most likely cause. Most computers these days will work well on a 700W power supply. They typically range from $ 50 to $ 100.
Motherboard Not Recognizing The Power Source
Every once in a while, the motherboard may not recognize the power coming from the AC adapter on the laptop or the outlet from a desktop. On a desktop unplug the power cord from the outlet (after shutting down the computer) and wait about 30 seconds. Plug the computer back and try powering it back on. In many cases this will work. Laptops need the battery and AC adapter unplugged, but the result is the same. This happens much more often on laptops than desks. It is still worth trying before anything else.
Short in the Motherboard
This is the most expensive cause for a no power issue. If all of the above does not work, then the cause is most likely the motherboard. Motherboard prices range from $ 100 to $ 700, depend on motherboard manufacturer and model. Labor prices are also high, as replacing a motherboard involves completely disassembling the computer. Everything than the computer needs to run is plugged into the motherboard.
Hopefully this article will give you something to think about when diagnosing a computer. Although, these are not the end all of no power issues, it is a very good start. These symptoms account for over 90% of power failures. The other 10% are usually caused by manufacturer / model specific problems. Resolving those issues can only come with some research. In the end, it all comes down to experience.