Why My PC is Not Turning On When the Motherboard Light is On?

So, you have pressed the power button on your PC, and nothing happens, even though the motherboard lights are ON?

This problem is usually due to a faulty power supply, which does not provide enough power to the motherboard.

It’s possible to fix the issue yourself, as long as it’s not a hardware failure. Here’s how!

1. Check the PSU cables

First, make sure all the power cables are properly plugged in. If there isn’t another wall socket available, use that to eliminate the outlet as the cause of the problem.

As PC power supply units age, they output less power over time.

For example, if you have a 300-watt power supply, after 2-3 years, it may provide different 300 watts to the motherboard, causing your PC to fail to turn on.

So, if your supply is quite old, I think its time for its retirement! Your PC will say thank you!

2. Power Cycle your PC

It’s straightforward. Here’s how to do that:

  1. Remove all the cables from your PC (power, monitor, keyboard, etc.)
  2. Press and hold the power button on the PC for 30 seconds.
  3. Wait for 3 minutes, and then plug it back in.
  4. Turn on your PC.

Did it fix the problem? If yes, good! No? You have two more solutions to try!

3. Remove and Re-Install RAM

Always disconnect your computer from the power before working on a motherboard.

Another note: Don’t touch the motherboard with your bare hands, even when unplugged. But why when it’s already disconnected from power? Well, the static charge on your hand can damage the motherboard components.

Take out the RAM from the motherboard and turn on your computer. If it starts this time and beeps, the issue might be with the RAM.

To confirm, turn it off, re-install the RAM, and turn it on again. If it doesn’t boot up, your RAM is faulty. If it boots, it was a temporary cache glitch.

4. Re-Install CMOS Battery

Re-installing the CMOS battery is your final DIY troubleshooting step. If this doesn’t resolve the issue, it’s likely a hardware malfunction in the power supply or motherboard.

Here’s what to do:

  1. Locate the CMOS battery on the motherboard. It is a small, round battery powering the BIOS chip of your computer.
  2. Remove it and wait for 3 minutes before re-installing it.

If your PC starts, great! If not, replace the CMOS battery.

If it’s still not working after replacing the CMOS battery, I’m afraid there’s a hardware malfunction with your computer’s power supply or motherboard.


About the Author

Muhammad Qasim

Muhammad Qasim

Muhammad Qasim is an Electrical Engineer, Solo Entrepreneur, and Web Developer who loves troubleshooting gadgets and making cool things for the internet.

You can contact him on Email, LinkedIn, Twitter, or GitHub.

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