Why Does My LG Monitor Say No Signal?

The message means no usable video is reaching the selected input. It doesn't prove that the screen is broken.

A power light or spinning computer fan doesn't confirm that the computer has started properly or is sending video. Likewise, a monitor can have power while waiting for a different input.

Open the monitor's own menu using its joystick or buttons. If the menu appears, the screen can display that menu, so check the connection and source next.

If neither the menu nor a power indicator appears, check the power connection first. A screen with no power needs a different approach from one displaying a No Signal message.

How do you check the input, cable, and ports?

Select the exact connected input, then reconnect the video cable with both devices off. Start with a direct connection between the computer and monitor.

Trace the cable from the computer to the monitor.
Read the label beside the monitor's connected port.
Choose that input in the monitor menu, such as HDMI 1 rather than HDMI 2.
Shut down the computer and turn off the monitor.
Disconnect and firmly reconnect both cable ends.
Turn on the monitor, then start the computer.

Look for damaged connector housings, bent contacts, or a plug pulled sideways by a tight cable. Hold the connector when unplugging, and release any latch before pulling.

Temporarily remove docks, splitters, switches, and adapters where a direct connection is possible. If the picture returns, add those parts back one at a time to find the failing link.

For USB-C connections, confirm that the computer port supports video output. Our guide to what a USB-C monitor is explains why the connector shape alone doesn't confirm video support.

Could the computer be sending video to another display?

Yes, the computer may be asleep or set to use another screen. Wake it, then check display settings from a screen that works.

On Windows, press Windows + P to open projection options and choose Duplicate or Extend when adding a display. Avoid cycling through options blindly if you can't see the menu.

On a Mac, open Displays in System Settings and check whether the external screen appears. Keep a laptop lid open during these checks so its built-in display remains available.

Check the computer output for an LG monitor with no signal

On a desktop with a separate graphics card, start with the video ports on that card. Ports beside the motherboard's USB and network connections may be inactive, depending on the computer's hardware and settings.

If the display worked before a resolution or refresh-rate change, restore a supported mode using another screen. A cable's maximum capability doesn't override the limits of the computer, adapter, or monitor.

A screen that shows the startup logo but loses the picture when the operating system loads points toward settings or graphics software. Check those before replacing the monitor.

How can you tell whether the cable or monitor is the problem?

Change one part at a time and record which combinations produce a picture. Replacing several parts together may restore video without showing what caused the fault.

Start with another cable that you know works, using the same ports. Then try another compatible video source on the LG monitor, or connect the original computer to another display.

Use these results to narrow the next step:

Another cable works: replace the original cable.
Another source works on the LG: investigate the original computer or its connection path.
The computer works on another screen: check the LG's input, supported modes, and ports.
The LG fails with known working sources and cables: contact LG support.

These are clues rather than proof of a single failed part. For example, another screen may accept a display mode that the LG doesn't support.

For broader help diagnosing a display setup, visit our monitor setup and fixes guide.

Which replacement cable fits your connection?

Choose by port type, signal direction, and required display mode. A higher bandwidth number won't fix an inactive output or the wrong input setting.

Silkland DisplayPort cable: for DisplayPort at both ends

The Silkland DisplayPort 2.1 Cable suits a computer and monitor that both have full-size DisplayPort ports. Silkland identifies this 6.6 ft cable as VESA-certified DP80, with 80 Gbps bandwidth and backward compatibility with earlier DisplayPort connections.

Choose it when you've isolated the original cable as the likely fault and want to keep a direct DisplayPort connection. Its higher bandwidth also gives room for a future setup that supports it.

Skip it if either device requires HDMI or USB-C. It doesn't convert those ports, and an older device will still operate within its own supported limits.

Measure the route before ordering. Leave enough slack to move the monitor without pulling on either socket, but avoid sharp bends behind the stand.

UGREEN DisplayPort to HDMI cable: for mixed ports

The UGREEN DisplayPort to HDMI Cable suits a computer's DisplayPort output connected to a monitor's HDMI input. It is one-way, so confirm the source and screen ends before buying.

This 6.6 ft cable supports 4K at 30 Hz, 1440p at 60 Hz, and 1080p at 120 Hz. Choose it when your required display mode fits those limits and the two devices lack a shared connection you can use directly.

Skip it for an HDMI computer output feeding a DisplayPort monitor input. Also skip it if you need 4K at 60 Hz, since that exceeds this cable's stated support.

At 30 Hz, pointer movement and scrolling look less fluid than at 60 Hz. For office work, check the desired refresh rate alongside resolution rather than buying on the word “4K” alone.

If your source is a Mac mini, our guide to the best monitor for Mac mini covers connection choices to consider.

When should you restart or reset the setup?

Restart after checking the physical connection, especially if video disappeared after sleep or a dock change. A restart can prompt the computer and screen to establish the connection again.

Shut down the computer, turn off the monitor, and disconnect the video cable. Reconnect it, select the correct input, and start both devices.

If needed, unplug the monitor's power briefly before reconnecting it. Follow its manual for model-specific power and reset instructions.

A factory reset is a later step because it clears custom picture settings. Record any settings you want to keep, and remember that a reset can't repair a damaged cable or enable an unsupported computer output.

When does replacing the LG monitor make sense?

Consider replacement after known working sources and cables fail, or when you also need a different screen for your work. Check repair and support options before choosing a new display.

The LG 27UP650K-W is a replacement option for office users who want a 27-inch 3840 x 2160 IPS screen at 60 Hz. It has HDMI and DisplayPort inputs and includes cables for both connection types.

Its height, tilt, and pivot adjustments suit a desk where screen position needs to change. Pivot is useful for long documents, while height adjustment helps place the screen comfortably without stacking objects beneath it.

Choose it for detailed text, spreadsheets, and general desktop work. Skip it if your main goal is high-refresh gaming or a direct USB-C connection, since its stated connections are HDMI and DisplayPort.

After setup, use the native resolution and adjust operating-system scaling until text is comfortable. Increasing text size through scaling preserves detail better than lowering the resolution simply to enlarge everything.

Our home office monitor guide helps match a screen to your workload. You can also compare Dell and LG monitors when choosing a replacement.

How do you prevent repeat connection problems?

Keep cables secure without putting strain on the ports, and change one setting at a time. This makes future faults easier to trace.

Leave slack for height and pivot adjustments, and keep plugs clear of objects pushed behind the desk. Don't sharply fold a cable or pull it by its jacket.

Before cleaning, switch off the monitor and follow its care instructions. Use a clean microfiber cloth, avoid spraying liquid directly onto the screen or ports, and keep connectors dry.

Label cables or note which input each computer uses if you switch between devices. Selecting the remembered input is quicker than unplugging a working setup.

What should you do if an LG monitor still says no signal?

Let the checks decide the next step for an LG monitor with no signal. Buy a cable only when its connector type, direction, and supported mode match the connection you need.

Choose the Silkland cable for DisplayPort at both ends, or the UGREEN cable for a DisplayPort source feeding an HDMI screen within its limits. Consider the LG 27UP650K-W only after isolating the fault or deciding you need a different display.

If the LG fails with known working sources and cables on the correct input, contact LG support with its model number and your results. If the computer fails on another screen too, seek help with the computer's video output.

For the next connection issue, use our monitor setup and fixes guide to choose the relevant checks.

Frequently asked questions

Why does my LG monitor say no signal when the computer is on?

A powered computer may be asleep, using another display, or connected through an inactive output. Match the monitor input to the cable, wake the computer, and check its display settings from a working screen; on a desktop with a separate graphics card, start with that card's ports.

How do I change the input on an LG monitor?

Open the monitor's menu with its joystick or control buttons, then choose the input connected to your computer. Match the exact port label, such as HDMI 1, HDMI 2, or DisplayPort; menu names vary by model, so use the monitor's manual if you can't find the input control.

Can a bad cable cause an LG monitor to say no signal?

Yes, a loose, damaged, or incompatible cable can prevent video from reaching the monitor. Reconnect both ends with the devices off, then try a known working cable that matches both ports; if you use an adapter, confirm its signal direction and supported resolution and refresh rate.

What should I do if my LG monitor still has no signal?

Connect the monitor directly to another known working video source with a known working cable. If it still shows No Signal on the correct input, contact LG support with the model number and your results; if another screen also fails with the original computer, investigate the computer's output.

Why Does My LG Monitor Say No Signal?