Computer monitor flickers on and off at startup [Fixed!]

An on-and-off flickering computer monitor at the startup can be frustrating. 

This problem may occur due to various reasons, including hardware or software issues, improper settings, or even an outdated graphic card. 

Fortunately, there are some easy ways to troubleshoot the issue and get your computer back up and running steadily with no delay as soon as possible. 

In this post, we will look into what causes a computer monitor to flicker on and off at startup and how to fix it efficiently so that you can return to work or entertainment without wasting any time.

Why does my computer monitor flickers on and off at startup?

The cause of your computer monitor flickering on and off at startup could be caused by various factors. 

The most common causes are damaged power cables, loose connections, and incorrect refresh rates can all lead to the monitor flickering. Additionally, some other factors are outdated display drivers or an issue with the monitor’s hardware could be the culprit. 

How to fix a computer monitor that flickers on and off at startup?

There are numerous reasons why computer monitors may flicker on and off at startup, including power supply issues or source signal problems. 

Before you try to diagnose and fix the issue, make sure that your power cord, HDMI cable, and other connections are securely attached. 

If you use an adapter or extension cord, check to see if it is working properly by powering on the power socket. 

After this step is complete, set the correct display refresh rate in your computer’s settings. 

Check your monitor’s display settings as well as its driver if any updates are necessary next. 

If none of these steps solve the problem it is likely a hardware issue with your monitor. 

However, there are some simple steps you can take first before coming to that assumption.

Here is a step-by-step process to fix this issue:

  1. Power Cycle Your Monitor
  2. Damaged Power Cable
  3. Damaged HDMI Cable
  4. Losse Cables Connection
  5. Check Power Socket
  6. Set the Correct Refresh Rate
  7. Check Display Settings
  8. Update Monitor Display Driver
  9. Check Your Graphics Card
  10. Monitor Hardware Issue
Computer monitor flickers on and off at startup [Fixed!]

1- Power Cycle Your Monitor

Following the power cycling of your monitor can help you fix the computer monitor flickering at startup. 

When your computer is excessively used, it may cause its monitor to flicker during startup due to overeating. 

Power cycling shuts off the device and then turns it back on, allowing hardware and software of equipment to reset which often fixes minor problems like flickering at startup. 

If the issue continues despite this, it might be because of loose or faulty cable connections, a loose power adaptor, or a hardware issue with the monitor itself. 

With proper care and maintenance for your computer monitor in spite of heavy use, you should be able to continue enjoying quality viewing for years together.

2- Damaged Power Cable

A damaged power cable can cause flickering issues in computer monitors when they turn on. 

This usually happens until the monitor is turned on for a few seconds, but it stops once the issue occurs. 

If you notice that your monitor flickers continuously or frequently even after a few minutes, it might be caused by an underpowered outlet or frayed or worn-out power cord.

In this case, replacing your old and damaged power cable with a new one should fix the problem immediately. 

Another potential cause of computer monitor flickering may be a bad video card or graphics driver.

3- Damaged HDMI Cable

If a computer monitor flickers on and off at the start-up, it may signify a faulty HDMI cable. 

As time passes by, these cables can grow old and worn out, resulting in flickering if used with a computer screen. 

If not checked regularly, an old and worn-out HDMI cable might result in permanent damage to the display of the monitor as well as other components. 

Before concluding that this is what’s causing the issue, first, check your HDMI cable for any frayed or broken wires. 

Additionally, try connecting another one of the same kind to see if that resolves the problem. 

If not resolved with another cable either, there could be something wrong with your monitor’s hardware or software.

4- Losse Cables Connection

When a computer monitor flickers on and off at startup, it is often caused by loose cables. 

Loose cables can cause insufficient power to be delivered to the monitor, resulting in flickering.

Common causes of loose cables are overtightening, age-related wear and tear, and improper installation. 

Overtightening occurs when the cables are connected too tightly to the port. 

This can strain the wiring and cause them to become disconnected or even broken after some time. 

Cables must be properly connected without being too tight. Age-related wear and tear is another potential cause of loose cables. 

Computer parts such as wires can become worn down over time due to regular use and movement. 

This may lead to slightly loose connections, which can interfere with power delivery, resulting in a flickering display.

5- Check the Power Socket

A computer monitor that flickers on and off at startup could result from a defective power socket. 

Power sockets can spark or make popping noises, which can cause flickering on the monitor. 

Additionally, the flickering could be caused by loose connections from the power socket to the monitor, resulting in insufficient energy being supplied to properly power up the display. 

If this is the case, reseating or replacing the cable connecting the power socket to the monitor might be necessary to resolve the issue. 

In other cases, a defect in a particular component on either an internal or external part of a hardware device may be causing a low voltage output to be generated when powering on.

6- Set the Correct Refresh Rate

The refresh rate of a computer monitor is the frequency with which it draws images from an incoming video signal per second. 

Computer monitors are designed to work optimally and deliver quality image output only when they receive certain refresh rates as input signals. 

If you set the incorrect refresh rate, there may be flickering at startup or during video playback because of synchronization issues between the operating system and your monitor. 

To ensure that this does not happen, you should adjust the settings in your operating system so that it uses the correct refresh rate all the time.

Here are some short points to set the correct refresh rate:

  1. Check the manual or specifications for your monitor to determine the optimal refresh rate.
  2. Open the Windows Display Settings menu on a Windows computer or the Apple System Preferences on a Mac.
  3. Find the menu to change your display settings and select “Display adapter properties” orAdvanced display settings.
  4. In the Display Properties or Advanced Settings window, select the “Monitor” tab.
  5. From the drop-down menu, select the “refresh rate” that matches the “optimal rate” for your monitor.
  6. Click “Apply” and then “OK” to save the changes.
  7. Restart your computer to ensure that the new settings take effect.

If adjusting these settings does not help reduce or eliminate flickering, then it may be necessary to check display settings.

7- Check Display Settings

When a computer monitor flickers at boot-up, it usually indicates that the display settings are not configured correctly. 

To fix this issue, users should always check their display settings to make sure that the resolution and refresh rate of their screen is set correctly for their system. 

Ensuring they have the latest hardware drivers installed can also help ensure the monitor displays properly. 

By making sure any operating system updates or graphics card updates have been installed they can also reduce flickering issues. 

Ensuring all connections between the monitor and graphics card are securely fastened can also prevent flickering problems.

8- Update Monitor Display Driver

Computer monitor flickering at startup is a common problem that can often be fixed by updating the display driver. 

When the display driver is outdated or corrupt, it can cause the monitor to flicker on and off at startup. 

Updating your display driver solves this issue by providing a more current version of the software, which contains bug fixes and other improvements from the manufacturer. 

To update your display driver, you must locate and download the latest version directly from your graphics card manufacturer’s website. 

Once downloaded, open up the installer file and follow the prompts provided by the installation wizard. 

After completing this process, restart your computer and check if the flickering has stopped.

9- Check Your Graphics Card

If you still observe flickering on your computer monitor as it starts up, it is likely that an out-of-date or faulty graphics card is to blame. 

It’s important that you check your graphics card for any problems causing the flicker. 

You can do this by going to the manufacturer’s website to ensure that you have the most recent drivers installed and configured properly. 

You may also need to perform system diagnostics on your computer to investigate if there are any hardware issues behind the flicker. 

Updating or replacing your current graphics card with a more modern one might be necessary in this case.

10- Monitor Hardware Issue

If your computer monitor is flickering on and off at startup, it may indicate there is a hardware issue with the monitor.

A faulty component in the monitor, such as the display cable or power supply, could be the cause of this problem. 

Another potential source of this issue could be an inadequate connection between the monitor and the computer’s video card. 

The first step to addressing this issue is to check all connections between the monitor and the video card. 

It is also recommended that you swap out components such as cables or power supplies to determine which component is causing problems. 

If these steps do not resolve the flickering problem then it maybe necessary to take the display device in for repair or replacement.


In conclusion, if your computer monitors flicker on and off at startup, you can troubleshoot your problem by following these steps:

  1. Power Cycle Your Monitor
  2. Damaged Power Cable
  3. Damaged HDMI Cable
  4. Losse Cables Connection
  5. Check Power Socket
  6. Set the Correct Refresh Rate
  7. Check Display Settings
  8. Update Monitor Display Driver
  9. Check Your Graphics Card
  10. Monitor Hardware Issue

If the monitor still flickers on after trying all these steps, the problem is likely with the monitor itself and should be sent in for repair or replacement if it is still under warranty.


Why is my monitor flickering on and off lines?

A flickering image or stripes on your monitor can be a frustrating experience. A loose or damaged cable is one of the most common causes of this issue. 

The cable may have become loose due to regular wear and tear or impact. 

If the video cable is damaged, it could cause the signal to break up and result in vertical or horizontal lines appearing onscreen. 

Other possible causes are:

  • A malfunctioning graphics card.
  • Drivers that are out of date.
  • Incorrect power supply.
  • Too high a resolution setting for your display.

Why is my LG monitor flashing on and off?

You may have a loose cable connection. Check all your connections on the back of your LG monitor and ensure that each plug is securely connected. 

If any connections are loose, secure them firmly into place and try turning on your monitor again. 

If this does not solve the issue, it’s possible that the internal wiring or components inside the monitor itself are malfunctioning or damaged.

Can faulty RAM cause the screen to flicker?

When there is insufficient RAM, the operations of your computer depend heavily on hard disk access because it is required to constantly switch data between the memory and hard drive. 

This might result in severe lagging or flickering while running graphics-intensive applications such as video editing software or games. 

Also, having inadequate RAM may slow down every action of your computer since it can’t store all necessary information in its memory which makes everything load slowly.

Why is my monitor flashing but not turning on?

The flickering you are experiencing with your monitor could be caused by various issues with its power circuitry. 

Power issues can range from a faulty power cable to a loose connection on the back of the monitor. 

Power issues can also be caused by a faulty power supply or a bad connection on the motherboard itself. 

Checking these connections and ensuring they are securely in place is a good first step when troubleshooting power problems with your monitor.

How do I fix my monitor not turning on startup?

When you are having trouble with your monitor not turning on startup, you should first consider updating your graphics card driver. 

The graphics card provides visual information to your computer from the monitor. 

Outdated drivers can cause various issues associated with poor rendering performance, difficulty connecting to displays, or even not booting at all. 

To update your graphics card driver, go to the manufacturer’s website and search for the latest version of the driver. Then, download and install it on your computer.

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