TL;DR
- “No Signal” is almost always one of three things: wrong input, bad/limited HDMI link (cable/port), or handshake mismatch (EDID/HDR/VRR/HDCP).
- First prove the TV port works with a known-good device, then simplify the chain (source → TV direct).
- Add complexity back one step at a time (AVR/switch, then 4K/HDR, then 120Hz/VRR).
- Power-up order matters when ARC/eARC or receivers are involved.
Quick diagnosis
- If the TV shows “No Signal” on one HDMI port but other ports work → that port or its settings are the issue.
- If direct source → TV works but through AVR/switch fails → the middle device (or its HDMI mode) is the bottleneck.
- If video appears in SDR but fails the moment HDR/120Hz/VRR turns on → bandwidth or feature negotiation is failing.
- If the picture flashes briefly, then drops → handshake/HDCP instability (often cable/port or a stuck HDMI controller).
When this usually happens
This usually starts after changing one part of the HDMI chain: swapping cables, adding a receiver/switch, enabling 4K/HDR/VRR, or after a firmware update that resets HDMI “Enhanced/Deep Color” settings. It’s also common when a source device wakes faster than the TV/receiver and the handshake happens in the wrong order.
Ranked fixes (fastest first)
1) Confirm the correct TV input (yes, really)
Make sure the TV is on the HDMI input where the source is connected.
If the TV times out and switches sources (common on some TVs), then it may look like a failure when it’s just on the wrong input.
2) Prove the TV port works with a known-good source
Plug a known-good device (streaming stick, console, Blu-ray) into the same HDMI port.
If the known-good device works on that port, then the TV port is fine and the original source/cable/chain is the issue.
If nothing works on that port, then switch to another HDMI port and continue troubleshooting there.
3) Simplify the chain to “source → TV direct”
Remove receivers, switches, soundbars (in the video path), and adapters.
If direct works, then the removed device is the problem (AVR/switch/soundbar passthrough), not the TV.
If direct still fails, then focus on cable/port settings and source output settings.
4) Cold-boot the chain (forces a fresh handshake)
Unplug power to:
- TV
- receiver/switch (if used)
- source device
Wait 60 seconds, then power on in this order:
- TV (let it fully boot)
- receiver/switch (if used)
- source
If the picture returns only after a full unplug, then the HDMI controller/handshake was stuck.
5) Force the TV HDMI port into the correct mode (Enhanced/Deep Color)
Many TVs have per-port settings like “Enhanced format,” “HDMI Deep Color,” or “4K/120 mode.”
If 4K/HDR/120Hz fails but 1080p works, then the port may still be in “Standard” mode and needs Enhanced enabled.
6) Step features back up in a controlled order
Start stable, then add features:
- 1080p SDR
- 4K SDR
- 4K HDR
- 4K 120Hz / VRR (if supported)
If it fails the moment you enable HDR, then bandwidth or HDR negotiation is failing (cable/port/middle device).
If it fails only when enabling 120Hz/VRR, then the chain can’t carry full HDMI 2.1 features reliably.
7) Receiver / switch passthrough settings (only if a middle device exists)
If you use an AVR or HDMI switch:
- Enable video mode “Through/Direct/Bypass”
- Disable scaling/conversion
- Enable 4K/8K “Enhanced” mode on the relevant input/output (naming varies)
If direct-to-TV works but through the receiver fails, then the receiver’s HDMI mode/port capability is the limiting factor.
8) Cable sanity check (especially for 4K/HDR/120Hz)
Swap to a short, certified cable for testing.
If a new short cable restores the signal at high bandwidth modes, then the original cable was marginal (even if it “used to work” at 1080p).
9) Adapter/dock isolation (only if an adapter is in the chain)
If you’re using any adapter/converter in the path, remove it and test direct HDMI.
If removing the adapter fixes it, then the adapter is the bottleneck or failing handshake.
10) Firmware updates (late-stage only)
Only after the above:
- Update TV firmware
- Update receiver/switch firmware (if used)
- Update source device firmware
After updates, re-check that HDMI Enhanced/Deep Color settings did not revert.
What usually does NOT help
- Factory resetting the TV before you’ve proven the port/cable/chain behavior.
- Randomly swapping settings without isolating “direct vs through AVR/switch.”
- Assuming the TV is “broken” when one HDMI port is just in Standard mode.
- Buying new gear before a cold-boot + direct test + controlled feature step-up.
Scenario example
Scenario example: A console works at 4K60 direct to the TV, but shows “No Signal” when routed through a receiver. A cold boot restores video temporarily, but enabling 4K120 breaks it again. Switching the receiver input to Enhanced/8K mode and using a short certified cable between receiver → TV stabilizes 4K120.
If you still cannot get a picture
Build a simple matrix:
- Which TV HDMI ports work?
- Which source devices work direct?
- Which cables work?
- Does the signal fail only when an AVR/switch is inserted?
- Does it fail only when HDR/120Hz/VRR is enabled?
If you can clearly show “direct works, through device fails,” you’ve already identified the root cause for support or replacement decisions.