Laptop Won't Show a Picture on the TV or Monitor Over HDMI: Causes and Solutions

Connecting a laptop to a TV to watch a film, or to a big monitor for work, is a simple job that sometimes turns into a puzzle. The cable's plugged in, but the screen says "No signal". Or there's a picture but it's cropped, flickering or silent. Or the monitor worked yesterday and doesn't today. There are quite a few causes, and most can be fixed without a repair. But sometimes a damaged port or the graphics chip is to blame, and then it's important not to waste time endlessly toggling settings.

The simplest causes

The wrong input on the TV or monitor

TVs usually have several HDMI inputs. If the cable is in HDMI 2 and the TV is showing HDMI 1, there'll be no picture. Select the source with the remote. On monitors, automatic input detection is sometimes switched off.

Windows projection mode

Windows can run in "PC screen only", "Duplicate", "Extend" or "Second screen only" mode. If the first is selected, the external screen gets nothing. Switch with Windows+P or in the display settings.

The cable

HDMI cables fail more often than you'd think: breaks near the plug, damage from doors and furniture, poor-quality cheap cables. High resolutions and refresh rates — 4K at 60 Hz and above — need a cable of the right version. An old cable may handle Full HD but struggle with 4K, causing flicker or signal loss.

Adapters and USB-C

Many modern laptops have no full-size HDMI port — only USB-C. You need an adapter or a USB-C-to-HDMI cable. But not every USB-C port carries video: the feature is called DisplayPort Alt Mode, and ports with it are usually marked with a DisplayPort or Thunderbolt symbol. Plug an adapter into a port without video support and there'll be no picture. Cheap adapters also often work unreliably, don't support the resolution you need or require extra power.

The graphics driver

An outdated or corrupted graphics driver is a common cause of external-display problems. After a major Windows update the driver is sometimes replaced by a generic one that doesn't handle external outputs properly. In laptops with two graphics chips — integrated and discrete — the HDMI port may be physically wired to the discrete GPU, so problems with its driver mean no picture on the external screen even though the built-in display works fine.

Resolution and refresh rate

If the laptop tries to send the TV a resolution or refresh rate it doesn't support, you'll see "No signal" or "Mode not supported". It most often happens when the laptop was previously connected to a different monitor with other settings. The fix is to set supported values in the settings.

Sound over HDMI

Picture on the TV but sound still coming from the laptop's speakers? HDMI carries audio too, but Windows doesn't always switch to it automatically. You need to select the TV as the playback device. If the TV isn't listed, there's a problem with the graphics card's audio driver.

A damaged port

The HDMI port is mechanically vulnerable. Cables are often inserted at an angle, knocked, or the laptop is dropped with a cable attached. The contacts inside bend, the plastic tongue breaks and the solder on the board cracks. Signs: the picture comes and goes as the cable moves, the plug is hard to insert or wobbles, or bent contacts are visible.

A separate danger is connecting to a TV or projector when the two devices are plugged into different ungrounded sockets. The potential difference can damage the port or the video-output circuits. It's safer to connect the cable with both devices switched off.

A graphics subsystem fault

Less often, the problem is the graphics chip itself or the video-output circuits on the motherboard. If no external display works via HDMI or USB-C, and the built-in screen shows artefacts or lines, there may be a hardware fault in the graphics subsystem that requires board diagnostics.

Narrowing down the cause

Try another TV input and another cable. Connect a different device to the same TV — if it works, the TV and input are fine. Connect the laptop to a different monitor. If the laptop won't output a picture anywhere through any cable, the problem is in the laptop. If it works with one device but not another, look at resolution settings or compatibility.

What our technician does

1. Checks projection modes, resolutions, refresh rates and audio settings.
2. Tests the port, cables and adapters with known-good equipment.
3. Updates or reinstalls the graphics drivers, including for the discrete GPU.
4. Recommends the right cable or USB-C adapter for your needs.
5. Repairs or replaces a damaged HDMI port and diagnoses the video-output circuits.

A real example

A café owner in Sololaki streamed football matches from his laptop to a big TV. One day the picture started dropping out every few minutes, then disappeared altogether. He bought a new cable, but it didn't help. Inspection showed the laptop had fallen off the edge of the counter several times with the cable attached: the inside of the HDMI port had broken and the solder on the board had cracked. We replaced the port, checked the video output and recommended a locking extension adapter that takes the strain off the laptop's port. The broadcasts run without interruption again.

Call a technician

If your laptop won't output over HDMI or the picture keeps dropping out, we'll come to any district of Tbilisi around the clock. Learn more on our laptop repair, driver installation and diagnostics pages.