The most common situation when a computer "won't turn on" is when the computer actually turns on but nothing is showing on the monitor. You see lights on your computer case, you might hear the internal fan running, you might even hear sounds, but nothing is showing on the screen.
When the computer turns on but nothing is displayed on the screen, the most likely problem is the monitor. It might be down, disconnected, or corrupted. However, you should also consider that peripherals connected to the PC or the computer itself could be the culprit. The following steps will help determine the cause.
If your computer displays a message on the monitor but still doesn't fully boot, see How to fix a computer that won't turn on for better troubleshooting guidance. We also have a unique solution for situations where your computer shuts down immediately after being turned on.
Try these common fixes in the order we cover them:
Test your monitor. Before you begin more complex and time-consuming troubleshooting of the rest of your computer, make sure your monitor is working properly.
After disconnecting the monitor from the computer, turn it on and off. If the monitor displays any type of diagnostic information, you know the monitor has power and is able to display content.
If you're planning to buy a new monitor, learn how to choose the one that's right for you.
Verify that your PC has completely restarted and is starting from a clean shutdown state. If you need help, see How to restart your computer.
The computer may appear to be "not turning on" when in fact it is just having problems resuming from standby/sleep or hibernation mode.
Press and hold the power button for 3-5 seconds to shut down the computer in power saving mode. After completely turning off the power, turn on the computer and test whether it starts normally.
If you are lucky enough to get a beep code, rule out the cause of the beep code. Beep codes can give you a good idea of where to look for the reason why your computer is shutting down.
Clear CMOS. Clearing the BIOS memory on the motherboard will restore the BIOS settings to factory default levels. BIOS configuration errors may be the reason why your PC won't boot completely.
If clearing the CMOS does solve your problem, make sure that any changes you make in the BIOS are done one at a time so that if the problem reoccurs, you will know which change caused your problem.
Verify that the mains voltage switch is set correctly. If the input voltage to the power supply is incorrect, your computer may not start completely.
If this switch is wrong, your computer will most likely not turn on at all, but incorrect power supply voltage may also prevent your computer from starting properly in this manner.
Reinstall everything possible in your computer. Reinstalling will re-establish various connections within your computer and is often the "magical" solution to problems like this.
Verify that all cables are connected correctly. For example, if the onboard graphics card is disabled and the VGA cable is plugged into it, nothing will appear on the monitor even if the computer is powered on. In this case, you need to plug the VGA cable into the correct video card.
Try reinstalling the following components and test if something appears on your computer screen:
- Reinstall all internal data and power cables
- Reinstall memory modules
- Reinstall all expansion cards
Reinstall the CPU only if you suspect that the CPU may be loose or incorrectly installed.
We treat this component separately simply because the chances of the CPU coming loose are very slim and installing a CPU is a sensitive task.
Check inside the computer for signs of electrical shorts. If you find them, then you need to investigate the cause of these electrical shorts.
Test your power supply. Just because your computer's fans and lights are working properly doesn't mean the power supply is working properly. PSUs tend to cause more problems than any other piece of hardware and are often the reason why computer components work selectively or intermittently.
If any of the tests you perform fail, replace the power supply immediately. After replacing the power supply (assuming you did this), leave the computer plugged in for 5-10 minutes before turning it on. This delay provides time for the CMOS battery (which may be exhausted) to charge.
Don't skip testing the power supply thinking the problem can't be with the PSU because "the device is getting power". Power supplies may work to varying degrees - a non-functional power supply will need to be replaced.
Start your computer with only necessary hardware. The goal here is to remove as much hardware as possible while still maintaining the computer's ability to boot.
For example, disconnect peripherals that are not required for the proper functioning of the computer, such as USB-connected storage devices.
If your computer boots normally with only the necessary hardware installed, continue to step 11. If your computer still doesn't show anything on the monitor, skip to step 12.
This step is easy for a novice to complete, requires no special tools, and can provide you with a lot of valuable information. If your computer still doesn't fully boot after performing all the above steps, you should not skip this step.
Reinstall each piece of hardware you removed in step 10, one at a time, testing after each installation.
Since your computer starts with only the necessary hardware installed, these components must work properly. This means that one of the hardware components you removed is causing your computer to not start properly. By reinstalling each device into your computer and testing each time, you will eventually find the hardware causing the problem.
Once the defective hardware is identified, replace it.
Use the POST card to test your computer's hardware. If your computer is still unable to display information on the monitor despite the necessary computer hardware being installed, a POST card will help you identify which remaining piece of hardware is preventing your computer from fully booting.
If you don't have one and are unwilling to purchase a POST card, skip to step 13.
Replace each critical piece of hardware in your computer with identical or equivalent spare hardware that you know is working, one component at a time, to determine which piece of hardware may be failing. Test after each hardware replacement to determine which component is defective.
If you don't have POST cards or spare parts to swap in and out, you won't know which piece of your important PC hardware is failing. In these situations, you have no choice but to rely on the help of individuals or companies that provide these resources.
Any question? Try these tips to fix a broken laptop screen.
FAQYes. Without RAM, your computer won't run, which means your display will be black when you turn on your computer. If you think this is causing display issues, try reinstalling RAM or installing new RAM.
When a monitor shows no signal, loose or faulty cables are often the culprit. Also, if your monitor has multiple source inputs, make sure you are using the correct source input.
The display may not turn on because your computer does not wake properly from sleep. Try waking the computer by shaking the mouse, pressing a key on the keyboard, or quickly pressing the power button. If your computer wakes up but your monitor is still sleeping, you can force it to wake up using the keyboard shortcuts Win + P or Ctrl + Alt + Del.
You can try turning on the Narrator feature available in Windows 11 and Windows 10. This screen reading app helps you navigate your display settings even if you can't see them. You can turn it on or off by pressing Win + Ctrl + Enter .
