Computer Motherboard Troubleshooting

The motherboard is the computer, so the usual symptom of a failed motherboard is a completely dead system. Fans, drives, and other peripherals may spin up if the motherboard is dead, but more often nothing at all happens when you turn on the power. No beeps, no lights, no fans, nothing.

If you think you have a dead motherboard, think again. The most likely cause of a dead system is a blown fuse or breaker at the wall receptacle. If you're certain the system is getting power and you have just installed the motherboard, it's much more likely that you've neglected to connect a cable or made some other basic error than that the motherboard itself is bad, assuming of course that the problem motherboard is a highquality product.

When Bad Motherboards Turn Good

Many online vendors have stopped accepting returns of "bad" motherboards for just this reason. As it turns out, about 19 of 20 motherboards returned as defective are perfectly good. The buyer simply didn't install the motherboard correctly. Even so, many upgraders choose to buy their motherboards from a big-box store or other local source, because of their generally better return policies. In fact, some people troubleshoot their systems by buying a motherboard locally and then returning it if the motherboard turns out not to be the problem. We think that's unethical, but as any vendor will tell you, it's common practice.

What's in a Name?

Most name-brand motherboards, particularly those made by Intel and ASUS, are of very high quality; cheap motherboards, including those used in most consumer-grade mass-market systems, are of very poor quality. We've used Intel and ASUS motherboards for years. In a shipment of 100 motherboards, it's unusual to find even 1 DOA. In a shipment of 100 cheap motherboards, it's not uncommon to find half or more DOA, and many of the remainder failing soon after they're installed.

In a working system, it's very uncommon for a high-quality motherboard to fail other than from lightning damage (see Computer Power Supplies and Protection) or other severe abuse. In particular, it's nearly unheard of for a motherboard to fail while it is running, as opposed to when you start the system. A dead system is more often caused by a dead power supply than a dead motherboard, so the first step to troubleshoot an apparently dead motherboard is to swap in a known-good power supply. If the system remains completely dead with a known-good power supply, it's likely that the motherboard is defective and must be replaced.

It's not uncommon for a motherboard to fail partially. For example, an ATA interface or the embedded video, audio, or LAN may stop working, while the rest of the motherboard functions appear to work normally. It's possible to work around such partial failures; for example, by disabling the failed function in BIOS Setup and installing an expansion card to replace the failed embedded function. We recommend against this practice, however, because a partial motherboard failure is often soon followed by a complete failure.

To set up your computer motherboard’s CMOS, BIOS, and chipset settings, see the Motherboard CMOS Configuration and Setup page for instructions and tips.

To update your computer’s BIOS system without replacing the motherboard, see the Updating Motherboard BIOS page for instructions and tips.

More about Computer Motherboards