Red CPU Light on Motherboard Fixes & Diagnosis

Many people get confused when they see the red light on their motherboard and most think it has to do with their CPU, that they have not placed their CPU properly or something like that, but from our experience that is not always the case , more often than not it is a problem with other components that are faulty or not seated/connected correctly.If your motherboard has a label that says “CPU” and the red light is on there, then it really has to do with the processor. But there could also be a few different reasons for this, don’t always assume a faulty CPU.

Why is there a red light on my motherboard?

If you see a steady red light on your motherboard, it’s usually an indication that the board hasn’t booted up properly and needs to be replaced or that one of the components is faulty or not properly connected. The system may not boot or have other issues as well. So continue reading this article and try the solutions we recommend as they often fix any problem. If the solutions we recommend don’t work, or if you’re not confident trying them yourself, please contact technical support for help determining if there is a hardware problem and resolving potential warranty conflicts.

See also  14 Ways to Make Earbuds More Comfortable

What does the red CPU light on the motherboard mean?

If your motherboard has a label that says ‘CPU’ with a red light above/below then it could really be CPU related, if not then there is probably a problem with another part, please try the other fixes after trying the ones we will mention below are CPU related only.

If your motherboard has a label that actually says CPU, there are a few things you can do to fix it:

1- The cooler may not be connected properly. If so, grab your cooler and try moving it. When plugged in properly, it won’t move at all because it’s well attached to the motherboard. This is one of the most common problems.

2- Try to remove 1 RAM Stick and try to boot with only 1 plugged in, if that doesn’t work then unplug the remaining Stick and plug in the one you removed before, this way you can test if any of the RAM Stick is defective. Although they are not completely related to the CPU, RAM often shows up as a CPU problem. If you manage to boot with 1 RAM Stick, it means that either:

  • The other stick is defective.
  • You didn’t connect the RAM in the right places
  • Incompatible RAM? (If they are different)

3- CPU power cable not properly connected to the motherboard. Make sure it is connected properly otherwise the CPU will not be able to get power hence the error.

4- PSU cannot supply enough power to run CPU properly. This is rare and if everything else is powered it most likely isn’t the reason, but it’s still a possibility. The PSU may be faulty and can only supply a tiny amount of power, just enough to power some components of the motherboard and not enough for the processor. If so, try using a different PSU if possible.

See also  How Often Should Thermal Paste Be Changed? [ANSWERED]

If none of the above exist, it may be a bent pin on your processor or it may just be faulty and you may need to return it for a new one or refer to an article on the scope of repairing bent pins if that is the problem.

Diagnosing the red light on the motherboard

If your motherboard just shows a red light and has labels to tell you exactly which part it’s having trouble with, there are a few things you can do to diagnose and fix the potential problem.

The first step in finding help for your computer problem starts with determining what type of error was detected by our computers when they were turned on – whether that be a power failure, memory errors, fan problems, etc.

Start with the basics, Connecting all cables correctly and making sure everything is connected correctly, which is often overlooked as a potential source of problems, but can go a long way towards solving problems.

When everything is connected properly, you can:

  • Run a RAM error check as that’s usually the problem.

Try to boot with only 1 RAM Stick, if it doesn’t work, unplug and plug in the other one and try again. If neither stick of RAM works, make sure they are connected properly and in the correct slots.

  • Make sure the GPU is properly connected to the motherboard.

Some people don’t connect the GPU well enough and it causes the red light error, you may need to apply a lot of force to the GPU until you are sure it is connected properly.

  • Make sure it’s not a problem that the PSU is faulty or not powerful enough.

If the motherboard is getting power, try removing the CPU or GPU and see if the red light goes out (if the other is getting power). The PSU may now be powerful enough to support the power consumption of both the CPU and GPU.

  • Disconnect the GPU completely and try to start.
See also  Is G-Sync Necessary?

You should be able run with only the CPU and the integrated graphics, if that works then it could be a problem with the GPU not being plugged in properly (motherboard detects the GPU is plugged in but not fully plugged in properly) or a faulty GPU.

Make sure it is properly connected to the motherboard, grab it and try to pull it. If it doesn’t move at all, it’s plugged in properly, if it moves even just a little bit, it’s probably not plugged in properly.

  • Reset the BIOS / Clear the CMOS

Your manual will probably have instructions on this or you can check the manufacturer’s website. It’s essentially a silvery battery that you have to remove for about 5 minutes and then plug it back in.

  • Unplug everything and try again

Just unplug everything and try plugging everything back in.

If none of the above works, there’s probably a processor problem (assuming you’ve tried booting without a GPU).

To be extremely rare in order for none of the above solutions to work, if they do, you should contact some local IT’s to try it out and see if they can find the problem.


Thank you for reading. We hope this post helped solve your red CPU light problem! If not, we recommend that you consult a local IT specialist before giving up the machine completely. They may be able to diagnose and repair the problem without sending it in for repair.

We invite readers who have had success or had any other advice on resolving this error code to leave comments below and share their experiences so others can benefit from what they’ve learned! Thanks again for reading our blog today!

Leave a Comment