LGLG TV No Signal on HDMI? Here’s How to Fix It

Hey! We’ll fix the LG TV “No Signal” on HDMI and get your picture back. Before we start swapping settings, I want to pinpoint which type of HDMI problem you have (wrong input vs handshake vs device output). Quick questions:
• What LG model is it (OLED / NanoCell / UHD) and about what year? (webOS version helps too.)
• What’s connected on HDMI: cable box, PS5/Xbox, PC/laptop, Apple TV/Fire TV, or an AV receiver / soundbar in between?
• Does the TV show “No Signal”, a black screen with sound, or “Not Supported” / “Invalid format”?
• Which HDMI port are you using (HDMI 1/2/3/4) — and is any port labeled ARC/eARC?

“Worked yesterday” usually means the TV isn’t dead — it’s typically one of these common causes of LG TV no signal on HDMI:

1) Wrong input / input name mismatch
• The TV may be on HDMI 1 while the cable is actually in HDMI 2, or the device is going through an AVR/switch and the TV input doesn’t match where the signal is arriving.

2) HDMI handshake / HDCP issue
• HDMI devices must “shake hands” (EDID/HDCP). After sleep mode or power outages, you can get a black screen or “No Signal” until you re-negotiate by power-cycling or changing ports.

3) Cable or port problem
• A loose connector, bent pin, or a port that’s slightly worn can trigger “No Signal” even if the cable “looks okay.” Trying another HDMI cable or port isolates this fast.

4) Output format/resolution mismatch
• If the PS5/PC output is set to a mode the TV can’t lock onto (rare but happens with some 4K/HDR/VRR combos), the TV may show “Not Supported” or act like there’s no signal.

We’ll fix this in a safe order that avoids random setting changes: input → power reset → cable/port → direct-connect → format settings.

Totally agree — no factory reset yet. Here’s the quickest “isolation test” sequence for LG TV HDMI no signal that usually gives a clear answer in 5–10 minutes.

Step 1 — Confirm the correct HDMI input
• Press Input/Source and choose the exact port your cable is plugged into (HDMI 1 vs HDMI 2, etc.).
• If you see the PS5 listed but still “No Signal,” that points more toward handshake/format or cable/port.

Step 2 — Reseat the HDMI connection (both ends)
• Turn off the TV and the PS5.
• Unplug HDMI from the TV and from the PS5, then plug back in firmly (you should feel it seat).

Step 3 — Power cycle (forces a fresh HDMI handshake)
• Unplug the LG TV from power for ~60 seconds (not just remote off).
• Unplug the PS5 power for ~60 seconds too.
• Plug TV back in first, turn it on, then power on the PS5 after the TV is fully up.

Step 4 — Swap ONE thing at a time
• Try a different HDMI port on the TV (move from HDMI 1 to HDMI 2), then select that input.
• If you have another HDMI cable, try it. (A known-good cable is the fastest proof.)

Tell me: after a full power cycle + different port, does the LG still show “No Signal”?

Sound but no picture is a classic clue: the HDMI link is “partially alive,” but video negotiation is failing (handshake/HDCP/resolution) rather than the TV being totally blind. Let’s tighten the diagnosis without guessing.

Step 5 — Remove any “middle devices” (if any exist)
• Make sure the PS5/laptop goes directly into the LG TV. No HDMI switch, splitter, capture card, or AVR in between. Those can trigger HDCP/handshake failures and create “black screen with audio.”

Step 6 — Check the LG HDMI format settings (webOS naming varies by model)
• On LG TVs there’s often a per-port setting like HDMI Deep Color / “4K” / “Ultra HD Deep Color.”
• If this is enabled for a port but the cable is older or the chain is unstable, you can get a “No Signal” or blank video.
• As a test: toggle HDMI Deep Color OFF for the port you’re using, then restart the TV and retry. (We can turn it back ON after the picture returns.)

Step 7 — Check SIMPLINK (HDMI-CEC)
• SIMPLINK/CEC helps devices control each other, but sometimes it causes weird input switching or handshake problems. Try toggling SIMPLINK OFF temporarily and retest.

After toggling HDMI Deep Color (OFF for test) + SIMPLINK (OFF for test), does the PS5 picture appear or does it still go black?

That result is super informative. It means your LG HDMI port is working, but the “high bandwidth” mode was failing. On LG TVs, enabling Deep Color/4K/HDR can raise the HDMI signal requirements, and then any weak link (cable, connector, or device output) turns into LG TV no signal on HDMI or a black screen.

Why it happens (in plain terms)
• 4K HDR 60Hz needs a stronger, cleaner connection than 1080p. If the HDMI cable is borderline (or the connector is loose), the TV can’t lock onto the video signal, so you get “No Signal” or picture drops.
• Some laptops also change output modes dynamically (resolution/refresh rate) and that can trigger repeated HDMI handshakes.

Step 8 — Get 4K/HDR back the right way
1) Use a known-good High Speed HDMI cable (for 4K/HDR) and avoid super-long cables if possible.
2) Try the PS5 on the TV port that supports full bandwidth best (many LG models have specific ports for 4K features).
3) Turn HDMI Deep Color back ON for that port, then do a clean restart of both TV and PS5 so they renegotiate from scratch.

For the laptop specifically: if you still see “HDMI no signal” sometimes, it’s often output settings (refresh rate/resolution) or a handshake timing issue. We’ll fix that next.

Yes — PC/laptop output is a top cause of LG TV no signal on HDMI because the computer may send a mode the TV doesn’t accept (or it sends it before the TV is ready). Let’s make it stable with a few targeted steps.

Step 9 — Force a “safe” display mode from the laptop
• Start with the simplest: set the laptop output to 1920×1080 at 60Hz and test. Once stable, step up to 4K later.
• If the laptop was set to a weird refresh rate (120Hz/144Hz) or HDR mode the TV doesn’t like, you can get “No Signal” or “Not Supported.”

Step 10 — Correct connection order (reduces handshake failures)
• Turn the TV on first and select the HDMI input.
• Then connect HDMI to the laptop (or wake the laptop after the TV is on that input).
This helps the laptop “see” the TV’s EDID correctly.

Step 11 — Disable features that can confuse the link (test only)
• If using a USB-C to HDMI adapter/dock, try a different adapter or plug directly if possible (docks are common failure points).
• Turn off HDR on the laptop temporarily and keep it at 60Hz until you confirm stability.

If you tell me Windows or Mac, I can give the exact clicks — but even without that, the 1080p/60Hz test is the fastest way to prove it’s an output mode issue and not a dead HDMI port.

Great details — and yes, HDMI ARC/eARC + CEC (SIMPLINK) can sometimes complicate input switching or handshake timing, especially if multiple devices wake up at once.

Step 12 — Make ARC predictable
• Keep the soundbar on the TV’s HDMI port labeled ARC/eARC only.
• Put PS5 and laptop on the other HDMI ports (not the ARC port).
• If the TV keeps bouncing inputs or devices disappear, temporarily toggle SIMPLINK (HDMI-CEC) OFF and test again. You can re-enable later if you need device control.

Step 13 — For the Windows laptop + USB-C hub
• Many hubs/adapters can’t reliably output 4K HDR at the refresh rate you want, even if they “sometimes” work. That’s why 1080p is stable but 4K is not.
• Try 4K at 30Hz as a test. If 4K/30 is stable but 4K/60 is not, the bottleneck is usually the hub/cable bandwidth or adapter quality.

So: ARC isn’t “breaking” HDMI by itself, but combined with CEC and a borderline USB-C hub, it can make “No Signal” and black screens show up more often.

You’re thinking about it the right way. Here’s the practical decision tree — it avoids wasted purchases and quickly identifies a real TV hardware issue.

When to replace the HDMI cable
• If turning on “Deep Color/4K/HDR” causes LG TV HDMI no signal or flicker, the first upgrade is a reliable high-speed HDMI cable (especially if the current one is old, long, or has been bent near the connectors).

When to replace the USB-C hub/adapter
• If 1080p is stable but 4K is unreliable, hubs are a common culprit. Try a different known-good USB-C to HDMI adapter or connect without the hub if your laptop supports it. If that fixes it, the TV is fine.

If NONE of the HDMI ports work
• If you test with a known-good HDMI cable + a second device (like a streaming stick) on multiple ports and every port says “No Signal,” then yes, it can indicate a TV-side issue (HDMI board/mainboard) — but that’s after you’ve eliminated cable/device issues.

If you want to avoid trial-and-error, open the chat and we can do a fast “two-device / two-cable / two-port” confirmation that tells you exactly where the failure is.

Awesome — that’s exactly the pattern we look for.

Summary: If you see LG TV no signal on HDMI, the most reliable full fix is:
• Confirm the correct HDMI input (HDMI 1/2/3/4) and reseat the cable on both ends.
• Do a real power cycle (unplug TV + device) to reset HDMI handshake/HDCP.
• Swap to a different HDMI port and test with a known-good HDMI cable.
• For 4K/HDR, ensure the cable/adapter can handle bandwidth; use LG’s per-port HDMI Deep Color correctly.
• For laptops/PCs, set a stable output (start 1080p/60Hz), then step up to 4K/30 → 4K/60 once stable.
• If ARC/eARC + SIMPLINK causes weird switching, test with SIMPLINK OFF to isolate.

Want me to tailor the exact settings for your LG model, PS5, and your Windows laptop adapter so it stays stable long-term? Open the chat and I’ll guide you step by step.