Computer Won't Turn On? Troubleshooting the Motherboard

Written by: Jesma • Edited by: J. F. Amprimoz
Updated Jun 3, 2009 • Related Guides: Motherboards | RAM

In this second installment to a series on troubleshooting a computer that will not boot up, we consider the power switch and motherboard as possible factors and discuss solutions.

continued from part one:

5. If you've eliminated the power supply as the source of your woes, the next step is to make sure your power button is sending the right signal to your motherboard - or any signal at all. I don't recommend anyone not very very comfortable with the inside of a computer attempt this troubleshooting step. Not all computers are the same. This step represents the majority, but not all.

Find the front-panel connectors. These may be bunched into one or may be 5+ individual, very small connectors. If you're lucky, each connector will be labeled. If you have to disconnect them to read the labels, make sure you write down or remember how to put them back. The connector you are looking for will be labeled "POWER SW" or "PWR SW" or something very similar to that. This indicates "power switch".
Remove the power switch connector from the motherboard, if you havn't already.
Plug your computer in.
Take a small, conductive screwdriver or other tool with a rubber grip and gently touch it to the two pins the power switch connector was attached to.

If your power switch was, in fact, the problem, then doing this should turn your computer on. Please note, however, that this troubleshooting step isn't 100% foolproof. In fact, it is very difficult to do correctly, and I always recommend getting a second opinion from a professional. Replacing a power switch is very hard to do, as most are proprietary to the case they came with. More than likely you'll need a whole new case. A case should only cost you between $20 and $50.

6. If all of these previous troubleshooting steps have failed, then it is highly likely that you're looking at a totally failed motherboard. This is a bad situation to be in because not only are motherboards costly in themselves, but you also have no way of knowing if whatever caused the motherboard to fail also knocked out your other components, especially RAM and Processor. A power surge can easily fry every component in a computer. That is why it is so important that you use power protection.

At this point it is probably best to take your computer to someone who has the tools and equipment available to test each component. Replacing a motherboard, like I said, can be very costly and labour intensive, so the bill you ring up at your local computer shop might be for a pretty penny. You will really need to count the costs and see if replacing the whole computer is possibly in your best interests.