The most visible and yet often the most underestimated part of any computer system is the monitor. It's where your movies play, your spreadsheets are displayed, and where your gaming adventures come to life. The slow but steady development and improvement of LCD and LED monitors over the past twenty years has brought higher quality displays within reach of the most limited budgets, to the point that older CRT monitors have all but disappeared from the market. Monitor flicker, unfortunately, did not follow CRT monitors onto the ash heap of history. Although newer monitors are much more reliable than older CRT technology, it is still possible for them to develop flicker. But don't panic – if your computer screen starts flickering, it doesn't automatically mean it's curtains for that hardware. It could simply mean that a driver update is required or that a change has been made in your Windows configuration.
In this article, I'll help you troubleshoot a flickering monitor so you can find out what's wrong and fix the problem.
Why a computer screen flickers
Although the display on your computer screen may look like a static image, it is actually not. Instead, the image is constantly being redrawn and erased at such a rapid rate that your eye cannot perceive it. A modern screen can refresh up to 100 times per second or more. This is called the refresh rate and is measured in Hertz. When you look at the specs of the monitor, you'll see a number like 60Hz, 100Hz, or something else. The number indicates the number of refreshes performed per second. On a 60Hz monitor, screen refresh occurs at 60 times per second. A 100Hz monitor will refresh 100 times per second. The faster the refresh, the faster the display reacts to changes and the smoother the experience. This is why 100Hz televisions have become so popular and why 100Hz computer monitors are ideal for games where the display is constantly changing.
Different people are more sensitive to cooling than others. Some people can use monitors as slow as 30Hz and still see a perfectly stable screen. Other people will be able to detect the refresh and see it as flickering.
How to fix a flickering computer screen
Check monitor cable
Both ends of a monitor DVI cable have screws to hold them securely in place, but not everyone uses them. Make sure both ends of the cable are secure and securely held in place. If securing the connection does not resolve the flickering, the cable itself may be faulty. Grab a spare cable and swap them out and see if that fixes the problem.
Check the power
Check that both ends of the power cable are also secure. An unsecured power cable can sometimes cause a screen to flicker and this is often accompanied by a buzzing sound.
Check display settings
If you recently updated your graphics driver, check the display settings to make sure nothing has changed. Right-click on an empty space on the desktop and select your display settings. The exact menu option varies depending on your video card manufacturer. On my PC, the entry says "NVIDIA Control Panel".
Open the Graphics Control Panel and select Change Resolution (labeled NVIDIA). Select the flashing monitor in the panel and make sure the refresh rate is at least 60Hz. If you have a 100Hz monitor, set it to that. Save changes and retest.
You can also check through Windows 10 settings. Go to Settings and System. Scroll down and select the "Display adapter properties" text link in the center area. Select the Monitor tab and check the refresh rate from there.
Check your graphics card
Problems with the graphics card can sometimes cause a monitor to flicker. These are unusual, but it is a possibility. If you have multiple monitors and only one is flashing, the problem is not with your graphics card. If all monitors, or your only monitor is blinking, it's worth checking.
Check that your graphics card is free from dirt and dust. Make sure the cooler fan is running and all case fans are spinning when they should. Use Speed Fan or a similar program to monitor your card temperature, as overheating is the root cause of most graphics card problems. If everything looks fine, it might not be your graphics card causing the flickering.
Check the monitor
The final potential cause of your computer screen flickering is the monitor itself. You can try to test it by changing the port you are using. If you are using DVI to connect to your computer, test using VGA or DisplayPort. If nothing changes, you may have to beg or borrow another monitor to test. Or test your monitor on another computer that you know works fine. If the monitor is flashing on a different computer or with a different hardware connection, then sad to say, your monitor has probably reached the end of its life. Monitors can be repaired, but unless your monitor is very high end and expensive, the repair is likely to cost more than just buying a new one.
I hope these suggestions help you diagnose your monitor's flickering issue. If you have any other suggestions for diagnosing monitor issues, please share them with us below!