I noticed some time ago on my personal site that a lot of people were searching for the answer to the above question. Chances are, if you’re asking the question above, you’ve encountered a situation where a technician is telling you "Your motherboard is bad. You either need a new one or you need a new computer." Naturally, if you’re not into the whole "computer hardware thing" you’re wondering just what the heck a motherboard is and why having a bad one is causing you some trouble.
(Technical folks, please note that I am intentionally simplifying a lot of what goes on inside a PC in this article to make it easy to understand what a motherboard does inside a system. I’m probably also taking some artistic license in places to make the concepts clearer to someone who doesn’t live and breathe technology like we do.)
What are the Major Components of a PC?
Most personal computers share the same collection of parts. But, just like each of us, there can be some differences between them. What I’m listing below are the most basic components that most personal computers contain (whether laptops, netbooks, or desktops) and what those components do. Your specific computer may have a different configuration, but the basic descriptions below will normally apply:
- Case: This is the external part of the computer. It’s the "box" that you pick up and carry when you move the computer around. By itself, it’s mostly a collection of metal and plastic with a couple of lights (LEDs) and switches. It doesn’t do much, and generally is the least likely component of your computer to cause you a problem.
- Power Supply: This is the part of your computer that takes electricity from the wall outlet, converts it into current and voltages that a computer needs, and supplies it to the other components of your computer. In the case of a desktop PC, it is mounted in the case at the spot where you plug in the power cord. For a laptop, it’s that device you plug into the wall and then connect to the computer. If your power supply is "bad", there is no electricity (or "not enough" electricity) getting to one or more parts of your computer.
- CPU (Central Processing Unit): Also referred to as the "processor", this component is the "brain" or "heart" of your computer. It’s the piece that runs programs, crunches numbers, and does most of the real "work" that the computer does.
- RAM (Random Access Memory): Also referred to as "memory" or (slightly incorrectly as "storage") this is the component of your system that acts as "working space" for the CPU. When the CPU needs to put a piece of data aside to work with later, it will store that data in the RAM. You might think of this as the "short term memory" in your brain, which helps you keep track of what you’re doing. When you power off your computer, what is stored in the RAM will disappear.
- Hard disk drive (HD): When you save a file on your computer, this is where it ends up. The hard disk drive is a partly mechanical, partly electronic device that uses magnetism to store information. Because a hard disk drive is a mechanical device, it is sensitive to shocks, vibration, and dust. It’s also one of the most common components in a computer to fail, for those reasons. When it goes bad, you’ll generally know it right away. You will often hear loud clicking noise, scraping sounds, or other unusual "mechanical" sounding noises from the computer. (Note that a certain amount of this noise is completely normal. But an excessive amount of it usually indicates a problem.)
- Video Card: This component takes digital signals inside the computer and converts them into something a computer monitor (the TV-looking screen you look at while using the computer) can display.
- Sound Card: This component takes digital signals inside the computer and turns them into sounds that you can hear through the speakers or headphones.
- Keyboard: This is the component that you type words and numbers on, that resembles a typewriter.
- Monitor: Also known as the "screen" or "display", this is the television-like device that displays the programs you’re running, the games you’re playing, etc. It’s most likely what you’re staring into in order to read these words.
- Mouse: This is the device you interact with to move the cursor (or arrow) around on the computer screen.
- Motherboard: This component is a large flat board, usually green, into which all the other components connect. The power supply gives electricity to the motherboard, which powers up the CPU, the RAM, etc. The motherboard also takes the electronic signals from the CPU, RAM, disk drives, video card, sound card, etc., and ensures that they flow from one device to another as needed. It’s something like the central nervous system in the human body.
Of all the components listed above, the motherboard is one of the most important. It’s the "central nervous system" that ties all the others together. When you press the power button to turn on your computer, it’s the motherboard that interprets the signal and tells the power supply to wake up and energize everything. It’s the motherboard that gives the CPU chip enough basic instructions (via something referred to as the "BIOS" or "basic input-output system") to get it going. When you save a file, the motherboard transfers that information from the RAM to the hard disk. When you click on something with the mouse, the motherboard recognizes the click and alerts Windows (or Mac OS X or Linux or whatever) that it has happened.
Symptoms of a Failed Motherboard
Given the motherboard’s many functions, the symptoms of a failed motherboard can range from very subtle to very extreme. A more subtle failure might result in the loss of sound, with all other functions appearing normal. A more extreme failure could result in the machine being unable to power on. In the middle of the range, you could see crashes (up to and including the "blue screen of death" or "kernel panic"), constant error messages, spontaneous reboots, or other erratic or unexpected behavior.
Diagnosing a failed motherboard is usually a process of elimination. The technician will typically begin disconnecting various components they suspect could be causing your problem, until they’re down to just the power supply, motherboard, CPU, RAM, and video card. Then they may connect a meter to the power supply to check the voltages it’s producing. Then they’ll likely try to remove and reconnect the remaining components to ensure they’re securely connected. They may swap those remaining components out with some that they know are good, to see if that solves the problem.
What Can You Do About a Failed Motherboard?
If you have a bad motherboard, your most obvious option is to replace it. Depending on the computer, this can be relatively easy.
Companies like HP, Dell, and Apple generally use customized motherboards in their computers. That can make the repair process more challenging because getting an exact match means either getting the replacement from the manufacturer or purchasing a used one from someone on eBay or in a used computer store. That doesn’t mean you have to throw the computer away. Most of the components inside the case are probably still good and still viable. Replacing the motherboard and (in some situations) the external case will allow you to salvage the CPU, RAM, etc.
Other manufacturers use "off the shelf" or "generic" motherboard that are not custom designed. These are built to certain standards (with names like "ATX", "ITX", and the like) which require them to have specific measurements, hole placements, etc., so that they are interchangeable. If your computer uses one of these, getting a new one or a working used one should be all you need. Transferring your CPU, RAM, etc., to the new board should solve your problem and get you going again.
If you’re not computer-savvy, though, I don’t recommend changing your motherboard yourself. Like many computer components, motherboards are sensitive to static electricity, incorrect voltages, etc., that can damage them. On the other hand, if you’re handy with a screwdriver and are willing to take the risk, replacing a motherboard will teach you a lot about what components are inside your computer and how they connect. (Just remember, if you fry your computer in the process, that’s not my fault!)
What Can Be Done About Other Failed PC Components?
Perhaps a technician has told you that your motherboard is fine, but something else is bad. What can or should be done? Here is some general advice about each component. Consider this just "something to consider" and make your own informed decision depending on your computing needs, budget, skill set, etc.
- Mouse or Keyboard: These components can be very inexpensive to replace (at least for desktop computers – laptops are a different matter). You may be able to pick up a keyboard or mouse that you like at a local computer store or online for as little as $5. If the rest of your computer is still viable, there’s no good reason not to replace these.
- Monitor: For laptops, especially newer ones, the monitor/display is one of the most expensive components. Depending on the value of your laptop and the price for which you can get a replacement display, it may be more economical to sell the laptop for parts and buy a new one. For desktops, where the monitor is a separate external piece, replacing it is about as simple as replacing a television. Unplug it from the all, disconnect it from your computer, and connect the new one. Pricing for these varies quite a bit, but depending on what you choose, you’ll be spending $50 or more for one. The nice thing about monitors is that they are something you can use for years and years, as long as they keep working. Generally speaking, monitors may outlast several computers.
- Sound Card: In some cases, these are built into the motherboard. If a built-in sound card fails, and the failure isn’t causing a system crash, you can often purchase and install a second sound card and use that. Sound cards are relatively inexpensive (though some professional models are very costly) and easy to install.
- Video Card: In some cases, these are built into the motherboard. If a built-in video card fails, and the failure isn’t causing a system crash, you can purchase and install a new (or used) video card and use that instead of the built-in video. Video cards range from relatively inexpensive to very expensive (for high-end gaming and CAD/CAM cards).
- Hard Disk Drive: When one of these fails, you’ve typically lost everything you saved on that computer. Hopefully, you thought ahead and had a backup. If not, a failed hard drive doesn’t mean you need a new computer. A new hard drive (generally a < $100 proposition) can be installed in a few minutes. Once installed, you’ll have to reload Windows (or Linux or Mac OS) from a CD or DVD. That process may take an hour or so to complete, but the end result will be a nice, fresh, working computer that will be more or less "like new". Hard disk drives, in my experience, generally fail in the first 90 days (if they’re going to fail early) or after about 3-4 years (once the warranty expires).
- RAM: RAM is a component of computers that tends to undergo a lot of change. There is a dizzying array of brands, standards, sizes, etc., out there. To decide whether or not to replace yours, you first need to identify what type your computer uses. That will mean looking it up on a vendor’s web site, checking your manuals, etc. Once you know what you need, have a look at local computer stores or Internet shops like Newegg.com to see if the type of RAM you use is available and what it costs.
- CPU: Like RAM, this is a component with a wide variety of models, and many of them are not compatible with one another. If your computer is relatively current, finding a replacement CPU should be easy. If it’s older, you may find a replacement cheaply on a site like eBay.com or via a local used computer store. If you can’t find a suitable replacement, that probably means you would end up buying a CPU, motherboard, and RAM in order to get the system going again. At that point, a new computer might be a less expensive option (but that’s a decision you need to make).
- Power Supply: Assuming your power supply didn’t die due to a lightning strike or power surge in your home wiring, the other components of your computer are probably still viable and functional. A replacement power supply will cost less than a new computer in most all cases, and will bring everything back to life. However, if the power supply died as part of a lightning strike or similar electrical issue, it’s possible that it took other system components with it. It’s worth trying to replace the power supply anyway, but if you replace it and things still seem to be bad, you’ll want to consider whether it’s worth replacing the other failed components.
- Case: Generally, these don’t fail. What does fail is the power switch (which can be replaced with a simple switch from Radio Shack or another electronic component store, though it may not be a visual match for the original) and the "lights" or LEDs that show power or disk activity. The LEDs aren’t essential to the function of the machine, so you could choose to live without them. But if you find them necessary and useful, LEDs can be found cheaply at electronics parts stores and aren’t usually much more difficult to replace than a light bulb.
Ultimately, whether you replace or repair your computer is your decision to make. If only a single component has gone bad, it’s probably going to be less expensive to replace that item than to buy a new computer. If several components fail, on the other hand, replacing the computer may be a better move. Chances are that the new computer will be faster than the old one and perhaps better in other ways. Only you can make that determination.