Symptoms
- Screen flickers or briefly loses signal
- Flicker gets worse or better when the cable is moved
- Problem disappears when switching to a different cable or port
- Flicker is worse at higher resolution or refresh rate settings
Likely causes
- CommonWorn or damaged HDMI cableRepeated bending or a manufacturing defect can break internal wires over time.
- CommonLoose HDMI port connectionA slightly worn port can lose full contact with the cable.
- CommonCable doesn't support the resolution/refresh rate combinationOlder HDMI cables may not reliably carry 4K or high refresh rate signals.
- Less commonInterference from nearby cables or electronicsRunning HDMI cables next to power cables can occasionally introduce noise.
What to do
- Inspect the cable for visible kinks, fraying, or a loose connector shell, and replace it if you see damage.
- Try a shorter, high-speed HDMI cable rated for at least the resolution and refresh rate you're using.
- Test a different HDMI port on the computer and on the monitor to rule out a worn port.
- Temporarily lower the resolution or refresh rate in Display Settings to see if flickering stops at a lower bandwidth.
- Reroute the cable away from power cords, speakers, or other electronics that could cause interference.
- If flickering persists on a brand-new high-speed cable in a different port, suspect the graphics card or monitor's HDMI input rather than the cable.
Tools and parts
- None
High-speed HDMI cableSearch: “HDMI 2.1 cable high speed”
When to call a pro
If a fresh cable in a different port on both ends still flickers, have a technician check the monitor's HDMI board or the computer's graphics output.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.