Fix General HDMI no-signal and handshake problems
This version is aimed at PC-to-TV/projector handshakes where EDID or color format mismatches cause the link to fail. If your laptop suddenly refuses to drive a 4K display or your projector blinks when HDR kicks in, use these PC-centric steps.
Quick checks to rule out simple issues
- Confirm the correct input
Double-check the display is on the HDMI input where the PC is connected. Projectors often time out and switch back to the previous source. - Inspect the HDMI cable
Look for sharp bends, kinks, or loose connectors. Try reseating both ends until they click into place, especially if a laptop dock is involved. - Test another HDMI source or display
If you can, plug a known-working device (like a streaming stick) into the same port, or plug your PC into a different monitor/TV. This quickly tells you which side is misbehaving. - Restart everything
Power off the TV or projector, the PC, and any receiver in between. Unplug them for 30 seconds before turning them back on.
Rebuild the HDMI connection step by step
- Start with a direct connection
If you normally run through a receiver or dock, temporarily connect the PC straight to the TV/projector with a short HDMI cable. This removes one variable while you troubleshoot. - Switch color format and bandwidth
On Windows, try YCbCr 4:2:0 or 4:2:2 at 10-bit instead of RGB 12-bit. On macOS, toggle HDR off, get stable SDR at 4K60, then re-enable HDR. - Match resolution and refresh rate
Set the source to a conservative resolution first—try 1440p60 or 4K at 60 Hz. Once you see a picture, you can step back up to higher frame rates. - Disable advanced features temporarily
Turn off VRR/FreeSync/G-SYNC and deep color while testing. These features sometimes cause handshakes to fail until the basics are stable. - Power on in a clean order
Turn on the display first and let it reach the home screen. Then power on the receiver (if used), and finally the PC. Some combinations really do depend on power-up order.
Expert tip: try a different HDMI cable, even if the old one “used to work”
Tip: A surprising number of no-signal problems end up being a marginal HDMI cable that only fails at 4K or at higher frame rates. Swapping to a short, certified Ultra High Speed HDMI cable is one of the fastest ways to tell whether you are chasing a wiring problem or a device issue.
If your dock or adapter seems flaky
Scenario example
Scenario example: A laptop dock sends 4K HDR to a projector. The image blinks off whenever HDR triggers. Switching the dock to 4:2:0 output, setting Windows to 4K60 SDR, and using a 6 ft Ultra High Speed cable directly from laptop to projector restores a stable picture. After that, HDR can be re-enabled without dropouts.
When to suspect the TV, source device, or receiver
- Source device problem – If the TV shows “No signal” no matter which port you try, but other devices work fine in the same port, the console or streamer may be at fault.
- TV problem – If multiple inputs intermittently lose signal for every device, check for a TV firmware update and consider a full factory reset after backing up your picture settings.
- Receiver or switch problem – If things only fail when a receiver or HDMI switch is in the chain, connect the source directly to the TV. If that works, review the receiver’s video pass‑through and 4K/8K settings.
If you still cannot get a picture
After verifying cables, ports, and basic resolution settings, persistent “No signal” or black‑screen behavior usually points to a failing port or a deeper compatibility issue. Document which combinations of source, port, and cable work or fail. Having that matrix ready makes support with General or your TV manufacturer far more effective and can help justify a warranty repair or replacement when simple fixes are exhausted.