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On this page
- Which kind of flicker do you have?
- 1. Cable and port: the cheap fix that works surprisingly often
- 2. Resolution and refresh rate
- 3. G-Sync, FreeSync and gaming features
- 4. Graphics driver or an app
- 5. Flicker at low brightness: PWM dimming
- 6. Power and interference
- 7. Is it the monitor itself?
- 8. Laptop screen flickering
- FAQ
Flicker comes in a few flavors: the whole screen blinking to black for a second, brightness that pulses, or a shimmer you only notice in dark game scenes. They have different causes. The good news is that the common ones are cheap, and you can rule most of them out in ten minutes without opening anything.
Which kind of flicker do you have?
Start here. The symptom points at the cause faster than any list of fixes.
| What you see | Most likely cause | Try first |
|---|---|---|
| Screen goes black for a second or two, then comes back | Cable, port or signal bandwidth | Reseat or swap the cable, try another port |
| Flicker only at high refresh rates, fine at 60Hz | Cable can’t carry the signal cleanly | A better DisplayPort or HDMI cable |
| Brightness flicker in games, often in dark scenes or loading screens | G-Sync or FreeSync (VRR) | Turn VRR off to test |
| Everything flickers except Task Manager | An app | Update or remove the app |
| Everything flickers, Task Manager included | Graphics driver | Reset, update or roll back the driver |
| Flicker you notice at low brightness, steady at 100% | PWM backlight dimming | Raise monitor brightness, see the PWM section |
| Flicker when a heater or other appliance switches on | Power or interference | Different outlet or circuit |
| Flicker on every computer you connect, and in the monitor’s own menu | The monitor itself | Built-in self test, then warranty |
One quick reality check: a phone video of your screen can show rolling bands even when the screen looks steady to your eyes. The camera adds those. Judge flicker by eye.
1. Cable and port: the cheap fix that works surprisingly often
- Unplug the video cable at both ends, check the plugs for bent pins or damage, and plug it back in firmly. Samsung’s flicker troubleshooting page starts with exactly this.
- Swap in a different cable you know works. Expected result: the flicker stops, and you’ve found it.
- Try another port on the graphics card and on the monitor.
- Still flickering at 144Hz or above? Drop the refresh rate to 60Hz for a test. How-To Geek’s DisplayPort guide notes that if a lower rate fixes it, that points at a low-quality cable.
A documented case: in a January 2023 r/Xiaomi thread, a new PC owner’s monitor went black every few seconds over DisplayPort, even in the BIOS, while the same monitor was fine over HDMI. Their update: a new DisplayPort cable fixed it. The bundled cable had been the problem all along.
Using VGA? Samsung recommends running the monitor’s Auto Adjustment.
2. Resolution and refresh rate
Samsung’s advice is to run the monitor at its native resolution and a refresh rate it supports. Set both on purpose.
- In Windows, go to Settings > System > Display. Pick the resolution marked “Recommended.” That’s the monitor’s native one.
- Then open Advanced display and choose a refresh rate the monitor lists in its spec sheet.
- Run the refresh rate test to confirm the browser gets that rate.
Stuck at 60Hz on a high refresh monitor, or the right rate missing from the list? That’s its own problem, with its own fixes, in our 144Hz monitor showing 60Hz guide.
3. G-Sync, FreeSync and gaming features
Variable refresh rate (VRR) lets the monitor match the game’s frame rate. It’s great when it works. When it doesn’t, you get brightness flicker, mostly in games.
- Turn VRR off as a test. On NVIDIA: open NVIDIA Control Panel, go to Display > Set up G-SYNC and turn it off. That’s the path Samsung gives. On AMD, switch off FreeSync in AMD Software or in the monitor menu.
- If the flicker stops, VRR was the trigger. You can leave it off, or check whether your monitor is certified for the mode you’re using.
- Turn off the monitor’s overclock setting if it has one. Turning off Overclock is one of the steps in Dell’s gaming monitor flicker guide.
- Also turn off motion blur reduction features like ULMB or MPRT, which Dell lists as a possible cause.
Dell is unusually direct about this. It lists several of its VA gaming monitors, including the S2422HG and S3222DGM, as not G-Sync Compatible and says flicker is expected if G-Sync is turned on with them. If your model is on a list like that, turning G-Sync off is the fix, and the monitor is fine.
4. Graphics driver or an app
Microsoft’s screen flickering guide has the neatest test on this page.
- Press Ctrl + Shift + Esc to open Task Manager and watch it.
- If Task Manager flickers along with everything else, the display driver is the likely cause.
- If Task Manager stays steady while the rest flickers, an app is the likely cause. Update it or uninstall it to check.
For the driver:
- Press Windows logo key + Ctrl + Shift + B. Microsoft says this resets the graphics driver. You’ll see a brief blink, which is normal.
- Started after an update? Roll the driver back: Device Manager > Display adapters > right-click the graphics card > Properties > Driver > Roll Back Driver. Those are the steps in Dell’s monitor troubleshooting guide.
- No rollback option? Install the latest driver from NVIDIA, AMD or Intel instead.
5. Flicker at low brightness: PWM dimming
Some monitors dim the backlight by switching it on and off very fast. That’s pulse width modulation, or PWM. TFTCentral’s explainer on PWM says the off periods get longer as you turn brightness down. That’s why flicker is easier to notice at low brightness, and at 100% the backlight is usually on all the time.
What you can try:
- Turn the monitor’s brightness up to 100% and see if the flicker goes away for you.
- If the screen is then too bright, TFTCentral suggests lowering brightness in the graphics driver’s color settings (or the contrast) instead of the monitor’s backlight control.
- Look up a review of your exact model that measured flicker with proper equipment. RTINGS describes its method on its image flicker test page.
A browser tool can’t measure PWM, and neither can we from a web page. And if screens give you headaches, mention it to an eye doctor. This guide can’t diagnose anything.
6. Power and interference
- Plug the monitor into a different wall outlet, not the same power strip.
- Move other devices off that power strip. Dell’s gaming monitor guide lists electromagnetic fields from nearby devices as a possible cause.
- Notice it when a heater or other high-current appliance switches on? Samsung lists those appliances on the same circuit as a cause, so try an outlet on a different circuit.
If the flicker shows up every time the space heater clicks on, the monitor isn’t haunted. It’s the circuit.
7. Is it the monitor itself?
Two checks settle it.
- Run the monitor’s built-in self test. Dell explains that if the self test passes, the problem isn’t the monitor, so look at the computer, cable and drivers. Your monitor’s manual has the steps for your model.
- Connect the monitor to a different computer or laptop. Samsung’s advice: if it flickers there too, the monitor likely needs service.
Flicker in the monitor’s own on-screen menu, with nothing connected, also points at the monitor. That’s a warranty question. Don’t open the case.
8. Laptop screen flickering
The cable steps don’t apply to a built-in screen, but the rest does. Run Microsoft’s Task Manager check, reset and update the graphics driver, and try a different refresh rate in Advanced display. If an external monitor plugged into the laptop is steady while the built-in screen flickers, the laptop’s panel or its internal cable is the likely problem. That’s a repair job. More laptop screen fixes are in the laptop hub.
If it can’t be fixed
If the monitor flickers on a second computer, with a known-good cable, or in its own menu, stop troubleshooting and contact the retailer (inside the return window) or the maker. Note the model, when it flickers and what you already tried. A short video helps, even if the camera adds banding of its own. Don’t buy a new monitor before trying a $10 cable, though. That’s the fix more often than the panel.
Frequently asked questions
Why does my monitor go black for a second and come back?
Usually the signal drops out. Reseat or swap the cable, try another port, and test at a lower refresh rate. If a lower rate fixes it, How-To Geek notes that points at a low-quality cable.
Can a bad HDMI or DisplayPort cable cause flickering?
Yes. Samsung and Dell both list a loose or damaged cable as a common cause. Swapping in a known-good cable is the quickest test.
Why does my screen only flicker in games?
Variable refresh (G-Sync or FreeSync) is the usual suspect. Turn it off to test. Dell says flicker is expected on some of its VA monitors if G-Sync is on, because they aren’t G-Sync Compatible.
Why does my monitor flicker at low brightness?
Many monitors dim with PWM, switching the backlight on and off quickly. TFTCentral explains that the off periods get longer at lower brightness, so flicker is easier to notice. Try 100% brightness.
Is monitor flickering bad for my eyes?
Some people say flicker gives them eye strain or headaches. We can’t give medical advice, so if screens bother you, talk to an eye doctor. Fixing the cause of the flicker is worth doing either way.
Related fixes
- Refresh rate test (free tool)
- 144Hz monitor showing 60Hz? How to fix it
- How to fix monitor ghosting
- Monitor fix guides
- Laptop screen fix guides
Sources
- Microsoft Support: Troubleshoot screen flickering in Windows, checked 2026-10-22.
- Samsung: Image is distorted, ghosted, or flickering on my Samsung monitor, checked 2026-10-22.
- Dell: Fix flickering on Alienware and Dell gaming monitors, checked 2026-10-22.
- Dell: How to troubleshoot a Dell desktop monitor, checked 2026-10-22.
- How-To Geek: Common DisplayPort problems and how to fix them, checked 2026-10-22.
- TFTCentral: Pulse Width Modulation (PWM), checked 2026-10-22.
- RTINGS: Monitor image flicker test, checked 2026-10-22.
- r/Xiaomi: Monitor blackouts every few seconds with DisplayPort (Jan 2023), checked 2026-10-22.
