My monitor flickers or flashes
A flickering screen is distracting and can cause headaches. The cause may be a cable, a setting, or occasionally a fault.
Look at when it happens
- All the time, or only sometimes?
- Only with one program, such as a game or video?
- Does it also happen on the laptop's built-in screen? If so, the monitor is probably not the cause.
Step 1: Check the cable
- Turn the monitor off.
- Unplug the video cable and plug it in again at both ends.
- Look for bent pins or damage.
- If you can, swap in a different cable. A worn cable is a very common cause.
Step 2: Check the power
Make sure the monitor power lead is pushed in firmly. If it is on an extension lead with many items, try plugging it into a different socket. Keep it away from large speakers or motors, which can interfere with the picture.
Step 3: Check the refresh rate
The refresh rate is how often the picture is redrawn. A wrong one can cause flicker.
On Windows, open Settings, then System, then Display, then Advanced display. Look for Choose a refresh rate and try the highest one on offer, or 60 Hz if unsure. Menu wording can differ by version.
On a Mac, open System Settings, then Displays and look for a Refresh rate option, where available.
Step 4: Restart and update
Restart the computer and install any waiting system updates. These sometimes fix display faults. Then try the monitor on a different computer. If it still flickers there, the monitor is likely at fault.
What to avoid
Do not open the monitor or its power adaptor. Even when switched off, parts inside can hold dangerous electricity.
When to get more help
If the flicker continues after a new cable and checking settings, we can help find out if the screen or the computer is at fault. Note the make and model and when it happens.