Why Won’t My Computer Turn On? How to Solve It?

If you want to know “Why won't my computer turn on?”, this post will explain it for you with 5 easy-to-follow guidance for troubleshooting “computer won’t turn on”.


By Irene / Updated on September 7, 2023

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Computer won’t turn on, and you might hear some sounds from the device. In this situation, your screen may remain black. Is this due to a simple power problem or a boot issue? Will it cause data loss? Don’t worry, now, we will share the causes of “Why my computer won’t turn on” and attach fixes for you to easily solving it.

Why won’t my computer turn on?

When your computer not turning on, the specific situation can be divided into 5 cases.

• The computer has power but refuses to start.
• The power supply shows a green light, but the computer remains inactive.
• The computer is unresponsive and won't power up or charge.
• The PC won't start, although the motherboard indicator light is illuminated.
• The computer is stuck with a black screen.

From the symptoms, we can infer the causes from two parts:

Physical causes Root causes

Monitor problem

Damaged hard drive due to corruption

A hard drive that is failing or approaching the end of its life

Power supply or battery malfunction

Malware or virus infection

Troublesome Windows update

Sudden system crash

Corrupted Master Boot Record

BIOS unable to detect boot drive

How to fix “My computer won't turn on”

If your computer is not turning on, these 5 fixes have proven effective in resolving the issue. Fixes 1 to 3 are suitable for addressing physical causes, while Fixes 4 and 5 target the underlying root causes.

Fix 1. Test your monitor and restart it again

First, make sure your monitor is working. Before you dive into more complicated computer problem-solving, do a quick check to ensure your monitor is okay.

Unplug your monitor from the computer and turn it off and on again. If you see any messages or information on the screen, that means your monitor is getting power and can show things.

Next, kindly confirm that your computer has restarted completely. If you're uncertain, you can try the following steps: turn off the computer by holding the power button, then turn it back on by pressing the power button. Repeat this process 3-5 times and check if your computer powers on.

check power button

It's important to know that sometimes a computer may seem like it's turned off, but it's just having trouble waking up from power-saving modes in Windows, like Standby, Sleep, or Hibernate.

Fix 2. Try another power socket

If your computer still won't turn on even after you've checked the monitor and restarted again, it might be having a power problem. In that case, you can try a different power socket.

check power source

Here's what you can do: unplug the cord from the current power socket and plug it into a different wall outlet that you know is working. If it's a laptop that's not turning on, but the power light is on, make sure you connect the charger and then attempt a different power socket.

Fix 3. Check the CMOS battery

Sometimes, an issue that's not very well-known is when a computer won't start, and you see the power supply light on. This can happen due to a problem with the CMOS battery. If the CMOS battery is old or damaged, it might not provide enough power to the BIOS chip, which is crucial for starting up the PC.

To tackle this, you can follow these steps: First, turn off your computer and make sure it's not connected to power. Find the CMOS battery on the motherboard, take it out, wait for about 15-20 minutes, and then put it back in. See if this helps with the issue. If your computer still doesn't respond, you might consider getting a new battery, and that could do the trick.

check cmos battery

Fix 4. Rebuild MBR

When the MBR is corrupted, it can cause your computer to have trouble starting up and may make it unresponsive. Rebuilding the MBR can be a helpful solution. Experienced Windows users have the option to use CMD to rebuild the MBR boot table. However, since the MBR plays a critical role in the boot process, any errors during this procedure can carry a significant risk of data loss and potential system crashes.

It is recommended to use AOMEI Partition Assistant Professional. This powerful computer management tool equipped with user-friendly interface and clear guidance that that simplifies the process of repairing a corrupted MBR for users of all skill levels.

Tip: You can use this software to create a special USB or CD/DVD that has the program on it. To do this, just install the software on a computer that's working fine.

Step 1. Insert a USB drive or CD/DVD into a functional PC. Launch AOMEI Partition Assistant Professional to create bootable media. Then follow the instructions to complete the process.

Make Bootable Media

Step 2. Boot your computer using the bootable device you created. You might need to modify the boot order in the BIOS settings. Once logged in, you will observe AOMEI Partition Assistant launching automatically.

Step 3. Right-click on the disk you wish to repair and select "Rebuild MBR".

Rebuild System Disk Mbr

Step 4. In the popup window, choose the appropriate type of MBR for your Windows system.

Choose Mbr Type

Step 5. Click on the "Apply" button located on the toolbar to execute the pending operations. Once completed, shut down your computer. Remove the USB drive or boot from the original disk during the subsequent boot-up process.


Fix 5. Reconfigure BIOS settings

At times, when your computer turns on but the screen is black after installing a new Windows update, it might be due to BIOS configuration problems. You can explore the BIOS and adjust its settings accordingly.

Step 1. If you have downloaded AOMEI Partition Assistant Professional, you can directly click “Tools” from the top menu, and choose the “UEFI BIOS Boot Options Manager” feature. Or if not, you can press the specific keys to enter BIOS.

uefi bios boot options manager tools

The key to enter BIOS will be different from the computer brands. You can visit the official website to find relevant information. Or you can try continuously press F2/F8/F11 or Del key.

Step 2. Access the boot menu, verify, and designate the OS drive as the primary boot drive.

select boot drive

If you're using Windows 11, make sure to enable UEFI and Secure Boot Modes in the BIOS as well.

Step 1: Go to the Boot section, pick UEFI/BIOS Boot Mode, and change it to UEFI if it's not already. Save your changes.

legacy to uefi

To enable UEFI boot mode, please check your partition table type. If it's not already in the GPT format, you'll need to convert it from MBR to GPT.

Step 2: Then, in the Security/Boot section, you can find the Secure Boot option and turn it on (if it's not already). Save your changes, and restart your computer.

selct secure boot

Last word

Why won't my computer turn on? In this post, we offer straightforward troubleshooting advice and share 5 helpful fixes to resolve the issue.

As you can see, AOMEI Partition Assistant can be a quite reliable tool in computer problems solving. You can use it to extend drive space, migrate OS to SSD, clone disk for back up, and so on. If you are Windows Server user, you can choose the Server Edition for compatibility.

Irene · Staff Editor
Irene is an Editor of AOMEI Technology. She devotes herself in giving insightful thoughts on common computer problems with simple and clear guidance. Irene loves to help people solve problems and explore more solutions on relevant issues. She loves reading, singing and travelling.