Keep Computer Audio and Video Working While Casting

Casting a computer screen to a TV can make a video easier to watch, but the picture may appear without sound or stop when you change what is shown. These steps help keep both audio and video playing by checking the connection, choosing the right sound output, and avoiding settings that interrupt playback.

What You’ll Need

A computer and TV that can connect by a casting method, such as built-in wireless casting or an HDMI cable.
A stable Wi-Fi network if casting wirelessly. Connect both devices to the same network when the casting method requires it.
The TV remote, so you can select the correct input or adjust the TV’s sound settings.
If using a cable, an HDMI cable and any compatible adapter needed for your computer.

Step-by-Step

Choose how to connect. Decide whether to cast wirelessly or connect with HDMI. Wireless casting is convenient, but it depends on network quality and may have a delay. HDMI usually sends picture and audio together over one cable. Some wireless methods mirror the whole desktop; others send only a video from a supported app or browser.
Check that the TV is ready. Turn it on and select the correct HDMI input if using a cable. For wireless casting, open the TV’s screen-mirroring or casting feature if it needs to be enabled. The feature’s name and location vary by TV. Confirm that the TV and computer are on the same Wi-Fi network if the casting instructions require that.
Start casting from the computer. On Windows, open the casting or display options and choose the TV or receiving device. The available command depends on the computer and wireless technology. On a Mac, use Screen Mirroring from Control Center or the menu bar when a compatible receiver is available. If you are casting from a browser or media app, use its cast or AirPlay control instead of mirroring the entire desktop. Follow the on-screen prompt on the TV if one appears.
Set the computer’s audio output. Start a video, then open the computer’s sound settings and select the TV, HDMI device, or wireless receiver as the output. On Windows, open Settings, then System and Sound, and choose the output device. On macOS, open System Settings, then Sound, and choose the TV or receiver under Output. Names differ between devices; select the output that corresponds to the active connection. If you want sound from the computer speakers instead, leave those selected, but note that some casting methods route audio to the TV automatically.
Check the TV’s volume and mute. Raise the TV volume to a moderate level and make sure it is not muted. If the TV is connected to a soundbar or receiver, check that device’s input and volume too. Avoid raising the computer volume to maximum to compensate for a muted or incorrectly selected TV output.
Test with a familiar video. Play a short clip and check that its picture and sound both reach the intended device. If only the picture appears, return to the computer’s sound output settings and select the TV or receiver. If sound plays only on the computer, check whether the chosen casting method supports audio. Some methods or apps mirror video without sending all system audio.
Keep playback from being interrupted. Temporarily prevent the computer from sleeping while it is plugged in and casting. On Windows, review Power & battery or power settings; on macOS, review Lock Screen or Battery settings. Choose a reasonable temporary display-sleep setting, then restore your usual setting afterward. Keep the computer awake if closing its lid would put it to sleep; closing the lid can stop casting on many computers.
Reduce interruptions and network strain. Pause large downloads or other high-bandwidth activity during wireless playback. Keep the computer within good Wi-Fi range and avoid moving it between networks. Close unnecessary video streams and apps if playback stutters, but do not close the app or browser tab currently sending the video.
Confirm the picture mode and resolution. If the TV shows a blank or unstable picture, check the computer’s display settings and use a resolution and refresh rate supported by both devices. With a cable, reconnect it firmly at both ends and select the matching TV input. With wireless casting, disconnect and reconnect if the TV is listed but not displaying the desktop correctly.
End the session cleanly. Stop casting from the computer or app before changing networks, unplugging HDMI, or turning off the TV. Restore your usual sleep and audio-output settings if you changed them. This reduces the chance that the next video will play through the wrong speakers or that the computer will stay awake unnecessarily.

Common Mistakes

Assuming picture casting includes audio. A method that mirrors the desktop may handle sound differently from an app’s built-in cast feature. Test both before settling in.
Choosing the wrong output device. The computer may keep sending sound to its built-in speakers or headphones after the TV connects. Check the output list again after connecting.
Using the wrong TV input. An HDMI connection can be working correctly while the TV displays another input. Match the selected input to the port in use.
Closing the laptop lid or allowing sleep. These actions can suspend the display, network, or playback. Adjust power settings temporarily instead of assuming casting continues in the background.
Expecting every video to cast the same way. Some apps send a video directly to the TV, while screen mirroring sends the desktop. Protected or otherwise restricted content may behave differently; use the service’s supported playback method rather than trying to bypass restrictions.

Tips

For a long session, connect the computer to power and keep it in a well-ventilated place.
Use a direct HDMI connection when wireless playback is unreliable or when you need fewer connection variables. Check that any adapter supports both video and audio.
Keep the computer, TV, and casting app reasonably up to date. Restarting either device can clear a temporary connection problem.
If wireless video lags, try moving the computer closer to the router or TV, depending on the casting setup, and reduce competing network activity.
Before changing multiple settings, make one change at a time and test. That makes it easier to identify what restored audio or picture.

Troubleshooting

Picture works, but there is no sound: Check mute and volume on the TV and any connected audio equipment. Then select the TV or receiver in the computer’s sound output settings. Disconnect and reconnect casting if that output is missing. If using an app, check its own audio controls and try a different supported casting method.
Sound works, but the TV picture is blank: Verify the TV input, reconnect the HDMI cable, or stop and restart wireless mirroring. If the computer detects the TV as a display, try a supported resolution and refresh rate. Restart the TV and computer if the display remains blank.
Audio comes from the computer instead of the TV: Choose the TV output explicitly. For wireless casting, check whether the selected method sends system sound or only the app’s video. If it does not send computer audio, use the app’s casting feature or HDMI instead.
Playback stutters or disconnects: Check Wi-Fi signal, pause heavy network use, and keep the devices on the required network. Restart the router only if other network checks point to a connection problem; then reconnect the computer and TV. With HDMI, test another compatible cable or port if available.
The connection stops when the lid closes or the screen goes dark: Reopen the lid, wake the computer, and check its sleep and lid-close settings. Keep the computer awake for the casting session. A screen turning off and the computer sleeping are separate behaviors, so review both display and power settings.
The TV does not appear in the device list: Confirm that casting is enabled on the TV, that both devices meet the method’s requirements, and that the network is correct. Restart both devices and try again. If the TV is not compatible with the computer’s casting method, use HDMI or a compatible receiver.

Frequently Asked Questions

Can I keep sound on my computer while showing video on the TV?
Sometimes. Select the computer speakers as the audio output if your casting method allows separate audio and video routing. Some methods send both together, so use HDMI or another supported option if separate routing is unavailable.

Why does sound switch back to my computer?
The computer may change its default output after a device disconnects, sleeps, or reconnects. Re-select the TV or receiver in sound settings after reconnecting.

Will casting continue if my computer sleeps?
Usually not reliably. Sleep can suspend playback or the network connection. Keep the computer awake during casting and restore your normal power settings afterward.

Is HDMI better than wireless casting?
HDMI is often more predictable for sending audio and video together, while wireless casting avoids a cable. The best choice depends on the devices, distance, and network conditions.

Why is a video app not showing the same thing as my desktop?
An app’s cast feature may send the video directly to the TV rather than mirror the desktop. That is normal. Use screen mirroring when you need the whole desktop, if the devices and content support it.

Do I need the TV and computer on the same Wi-Fi?
Many wireless casting methods require this, but requirements vary. Follow the instructions for the specific TV, computer, or receiver; HDMI does not require Wi-Fi.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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