Symptoms
- Screen goes black for a second then comes back
- Flicker happens at scene changes or specific content
- Only happens with one source, not others
- Worse since adding a 4K or HDR-capable device
Likely causes
- CommonHDMI cable not rated for the resolution/bandwidth in use4K HDR and high refresh rate signals need higher-bandwidth cables than standard HDMI cables provide.
- CommonHDCP renegotiation between devicesSome devices briefly renegotiate copy-protection at certain points, causing a flicker.
- PossibleReceiver's HDMI board can't fully support the source's formatOlder receivers can struggle with newer 4K120 or advanced HDR formats.
- PossibleLoose HDMI connectionA cable not fully seated can intermittently drop signal.
What to do
- Reseat every HDMI cable in the chain (source to receiver, receiver to TV) firmly.
- Replace cables with ones rated 'Premium High Speed' or 'Ultra High Speed' depending on your resolution needs.
- Try lowering the source's output resolution or disabling HDR temporarily to see if flicker stops.
- Update firmware on the receiver, TV, and source device.
- If the receiver has an HDMI passthrough/bypass mode for 4K signals, try enabling it.
- Connect the source directly to the TV to confirm whether the receiver is the point of failure.
Tools and parts
- Ultra High Speed HDMI cable
Ultra High Speed HDMI cableSearch: “48Gbps Ultra High Speed HDMI cable”
When to call a pro
If flicker continues with certified cables and updated firmware, the receiver's HDMI board may not fully support the source's format and could need professional evaluation or replacement.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.