Guides · November 4, 2026
PC connected to TV by HDMI: no signal, no sound, or the picture is cut off
Plugging a computer into a TV with one HDMI cable should be the easiest thing in the world, but the first time you do it, a few small problems often show up. Here they are by symptom, each with the most common cause first and then the fix.
1. The TV says "No signal"
- Wrong input on the TV: TVs usually have several HDMI ports (HDMI 1, HDMI 2…). Press the Source / Input button on the remote and choose the one the cable is plugged into.
- The PC isn't sending a picture: press
Win + Pon the computer and choose Duplicate or Extend. If "PC screen only" is selected, the TV gets nothing. - Plug in first, then start up: some older PCs and graphics cards only detect the TV if it is connected before boot. Unplug and replug, or restart the computer.
- Cable or port problems: try another cable or another HDMI port on the TV. Cheap adapters (USB-C to HDMI, DisplayPort to HDMI) are a common cause of "No signal".
2. There's a picture, but the sound still comes from the PC
HDMI carries sound too; Windows just hasn't switched to it:
- Click the speaker icon at the bottom right of the taskbar and choose the TV as the output device (usually shown with the TV brand or "HDMI").
- If the TV isn't in the list, open Settings → System → Sound and check whether the device is disabled. Also make sure the graphics driver is installed; HDMI audio comes from the audio part of the graphics driver.
- If you use an adapter, check that it supports audio. Some cheap VGA-to-HDMI adapters carry picture only.
3. The edges are cut off and the taskbar isn't fully visible
That is the TV's "overscan": TVs enlarge the picture slightly by default. You don't notice it with TV shows, but with a computer the edges get cropped.
- In the TV's picture settings, look for Overscan, Screen Fit, Picture Size or Aspect Ratio and choose Just Scan, Screen Fit, 1:1 or Full Pixel (the name varies by brand).
- If you can't find it on the TV, many graphics control panels have a scaling or "adjust desktop size" option that can compensate.
4. Text looks blurry or has colored fringes
- TVs process color for video by default, which makes text soft. Turn on PC mode, Game mode or Computer mode in the TV settings, or rename that HDMI input to "PC" (some brands switch modes this way).
- Use the TV's native resolution: 3840×2160 for a 4K TV, 1920×1080 for a 1080p TV. If text is too small on a 4K TV, set Scale to 150–200% in Display settings.
5. A 4K TV only runs at 30 Hz and the mouse feels sluggish
- 4K at 60 Hz needs an HDMI 2.0 (or newer) cable and port. Older cables top out at 30 Hz; use one labeled HDMI 2.0 or 2.1.
- On many TVs only some HDMI ports support 4K at 60 Hz (often labeled "4K@60" or "HDMI 2.0"). Move the cable to that port.
- The computer's graphics and port also have to support 4K at 60 Hz. On an older PC, 1080p is often smoother.
6. The TV goes black after a while
- Usually the computer went to sleep or turned off the display. In Settings → System → Power, set "Turn off screen" and "Sleep" to Never, or at least longer than one show.
- The TV itself may also have an auto power-off or energy-saving setting; turn it off in the TV menu.
- Want to run a laptop with the lid closed? See Keep a laptop playing on the TV with the lid closed.
7. It works, but you have to walk to the PC every time
This is the most common complaint about using a PC with a TV. The options: a wireless keyboard and mouse (cheap, but clicking small text from the sofa gets tiring); remote-desktop apps on your phone (they work, but the whole desktop on a small screen is hard for kids and grandparents); or a dedicated "playback remote", where the phone or tablet shows only a wall of video covers and tapping one plays it full screen on the TV.
Summary
No signal: check the TV input and Win + P. No sound: switch the sound output device. Edges cut off: turn off overscan. Blurry text: turn on PC mode. Black screen: turn off sleep. Once those are set, the TV works great as the computer's big screen.