What the Red Light on a Motherboard Means (and How to Fix It)

Learn what the ominous red light on a motherboard means, and how to stop it.

A red light on your motherboard means internal hardware is either plugged-in incorrectly or not working.

  • Internal hardware examples include the CPU, RAM or a graphics card.
  • Sometimes a dead CMOS battery may be the culprit.
  • Boot errors on the hard drive where the primary OS is installed may also cause the red light.

The red light always appears after the computer has been turned on, but generally it will not boot, enter the bios, or display content on the monitor.

The specific error depends on the motherboard and where the red light is located. Some motherboard manufacturers include labels on the board to explain what’s wrong. Older motherboards may have a single, unlabeled red LED, which makes it more difficult to discern what’s going on.

If you cannot tell what’s wrong at a glance (something's not plugged in correctly, etc), you can always refer to the user manual included with your motherboard.

How to Read a Red Light on a Motherboard

MSI Motherboard LED Labels

There are four main indicators newer boards have, and the red light will be located next to each label. Those are:

BOOT: A red light near the BOOT indicator means there is something wrong with the boot devices, which would be the hard drive. More specifically, it’s the hard drive where the OS is stored.

VGA: A red light near the VGA or GPU indicator means the graphics card is not detected or seated properly.

DRAM: A red light near the DRAM indicator means that a RAM module has not been seated properly. If you can see that side clamps on either side of a RAM stick are not locked down, that's probably the issue.

CPU: A red light near this indicator means the motherboard does not recognize the CPU, which could mean a number of things. It’s possible the CPU is not plugged in correctly or one of the pins is bent. It could also be the CPU fan is not plugged in. Finally, a dead CMOS battery can also cause the red light to trigger.

Important:

Older motherboards (made before 2015) will have a single red LED to indicate there is a hardware malfunction, but they don’t include any information as to what’s wrong. To find the culprit, you will need to remove all of the hardware, leaving no connections, and then plug them in one-by-one.

What Does a Red Light in CPU Indicate?

Each motherboard LED tells you where the problem is, but not necessarily what it is.

The red light near the CPU label indicates that something is wrong with the processor, and it’s one of the more common reasons why you will encounter the red light.

Here are some reasons why the CPU indicator would trigger:

  • It may not be seated properly, which can mean it’s not plugged in correctly or the pins are bent. 
  • It may also mean the motherboard’s power cable is not plugged in correctly.
  • The CPU fan cable is not plugged into the header all the way.
  • The CMOS battery is dead.
  • The CPU you have installed is defective.

How to Troubleshoot Red Light Errors on a Motherboard

These steps apply to all motherboard models, including older boards without labeled LED indicators.

Always make sure the power of the computer is off, and the power supply switch is set to 0 before disconnecting or connecting any internal hardware.

  1. Disconnect the affected hardware and reseat it to make sure it’s plugged in properly. If you have an older board you can skip this step.

  2. Reset the bios of your motherboard. Most of the time, it’s a jumper that you can short (by plugging in a jumper). You will need the user manual for your board if you don’t know the steps to do this. You might also check the official support website of your motherboard’s manufacturer. Alternatively, you can remove the CMOS battery and leave it out for at least five minutes.

  3. Replace the CMOS battery. A dead battery will trigger a red LED indicator, which can leave you pulling out your hair. You may even consider trying this first before anything else.

  4. If all else fails, disconnect and unplug all hardware starting with the GPU, any hard drives, the RAM, and the CPU. Look at the connectors and pins to see if there’s any damage or debris present. Grime and dust may build-up on an old motherboard which can cause problems. You can remove it by carefully cleaning the connectors with a soft pencil eraser. You should also remove all external peripherals including the mouse, keyboard, external drivers, printers, and ethernet cable.

  5. One by one connect the devices into your computer and try booting it up. Critical hardware includes the CPU and RAM. If you have multiple RAM modules you can leave one plugged in and the rest disconnected. If the computer appears to boot and there is no red light present, even when there is no video, then it’s likely you’ve found the problem. Try booting without the GPU (graphics card), and a single stick of RAM.

  6. If you’ve checked all parts and the problem persists, the problem may be either a defective motherboard, or a dying or defective power supply. In some cases, when the power supply fails, it still supplies power to the motherboard and components, and everything including the system fans will turn on, yet the computer will not boot.

How Can You Tell if Your Motherboard Is Dying?

The best way to tell if your motherboard is dying, or failing, is to follow the troubleshooting steps discussed here. Unplug all minor hardware from the board and attempt to boot with minimal connections.

If the computer still won’t turn on, or POST, then it's likely that either the board or the power supply is the culprit. More often than not, the power supply is the problem, however, if you replace the power supply and the computer still doesn’t boot, you know it’s the motherboard.

In rare cases, you may be able to detect damage on the board, including burnt or defective headers, transistors, and other components. A board that has been killed by a static shock will not show any signs of damage, however.

Why Does My Motherboard Have an Orange Light?

An orange light, usually solid, means there is power being supplied to the motherboard, which is normal. Some motherboards may display a persistent orange light, while others will not.

With select computers, the power button may flash different colors to indicate a problem. A solid orange light means there’s a problem with the motherboard, while a blinking orange light means there’s something wrong with the power supply.

FAQ
  • What does a red flashing light mean on an AMD motherboard?

    A red blinking light could appear because of a video card issue, built-up debris, or a CPU recognition error. Look to see which indicator is lighting up, if labeled, and run through the steps above. Consult the user manual or customer support if the documentation doesn't offer details about what blinking or solid light patterns indicate.

  • Why is there a red LED light on the motherboard after I installed RAM?

    This light could mean that your RAM is faulty or not correctly seated. Check that it's secure and make sure you're putting it in the correct slot or according to the manufacturer-recommended configurations. Also, double-check that you've purchased compatible RAM for your machine.

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