Troubleshooting Slack video and audio call issues typically involves a systematic approach to identify and resolve common technical problems. Whether you're experiencing microphone failures, video not working, or poor call quality, most issues can be fixed by adjusting settings, clearing cache, or checking hardware connections. Slack provides built-in tools like connection tests and audio/video troubleshooting options, while general steps like restarting the app or updating drivers often resolve persistent problems.

Key findings from the search results include:

• Cache clearing is the most frequently recommended solution, fixing microphone issues 90% of the time according to user reports ^[2]
• Built-in troubleshooting tools in Slack's Preferences > Audio & Video section allow users to test microphones, cameras, and network connectivity ^[4][6]
• Hardware checks like ensuring webcams are uncovered and properly selected in settings resolve many video issues ^[7]
• Driver updates for cameras and audio devices are critical for persistent problems ^[7]

Troubleshooting Slack Video and Audio Call Issues

Audio Problems and Microphone Failures

Audio issues during Slack calls often stem from incorrect settings, hardware problems, or software conflicts. The most effective first step is clearing Slack's cache, which resolves microphone problems in the majority of cases. For persistent issues, Slack's built-in audio testing tools and system-level checks can identify whether the problem lies with the application or your hardware.

Start with these essential steps:

• Clear cache and restart: Navigate to Help > Troubleshooting > Clear Cache and Restart in the desktop app. This fixes microphone issues 90% of the time according to user reports ^[2]
• Verify microphone selection: In Slack, go to Preferences > Audio & Video and ensure the correct microphone is selected. Test it directly in this menu ^[4][8]
• Check system audio settings: On Windows, verify microphone privacy settings allow Slack access. On macOS, check System Preferences > Security & Privacy > Microphone permissions ^[3]
• Run Slack's audio test: Access this through Preferences > Audio & Video > Troubleshooting > Run a Call Test. This checks both input and output devices ^[6]

For problems that persist after these steps:

• Update audio drivers: Outdated drivers frequently cause microphone failures. On Windows, use Device Manager to update audio drivers. On macOS, check for system updates ^[7]
• Disable conflicting applications: Other communication apps (Zoom, Teams) may monopolize your microphone. Close these before testing in Slack ^[4]
• Check physical connections: For external microphones, ensure they're properly connected and not muted. USB microphones may need to be unplugged and reconnected ^[7]
• Test with another application: Use your system's voice recorder or another app to verify if the microphone works outside Slack ^[8]

If audio works in other applications but not Slack, the issue likely lies with Slack's permissions or settings. Reinstalling the Slack app can resolve deep-seated software conflicts, though this should be a last resort after trying all other troubleshooting steps ^[9].

Video Call Issues and Webcam Problems

Video problems in Slack calls typically fall into three categories: your camera not working, others not seeing your video, or poor video quality. Each has distinct troubleshooting paths, though they share some common solutions like checking hardware connections and updating drivers.

Begin with these fundamental checks:

• Verify camera selection: In Slack's Preferences > Audio & Video, ensure the correct camera is selected. Laptops often have multiple camera options ^[7]
• Check physical camera: Ensure no physical shutter is covering the lens. External webcams should be properly connected and powered ^[7]
• Update camera drivers: On Windows, update through Device Manager. On macOS, check for system updates that include camera driver improvements ^[7]
• Run Slack's connection test: This checks both video and network performance. Access it through Preferences > Audio & Video > Troubleshooting ^[6]

For specific video issues:

• If others can't see your video:
• Ensure you've granted Slack camera permissions in your operating system settings ^[7]
• Check that you haven't accidentally turned off video during the call (the camera icon should not be crossed out) ^[4]
• Test your camera in another application to isolate whether it's a Slack-specific issue ^[8]
• If you can't see others' video:
• Verify the presenter is actually sharing their video (look for the camera icon next to their name) ^[7]
• Check if the video window is minimized or hidden behind other application windows ^[7]
• Ensure you haven't enabled any bandwidth-saving settings that might disable incoming video ^[5]
• For poor video quality:
• Check your internet connection speed (Slack recommends at least 1.2 Mbps for HD video) ^[5]
• Close other bandwidth-intensive applications during calls ^[4]
• Lower your video resolution in Slack's settings if connection issues persist ^[7]

Advanced troubleshooting steps include:

• Reinstalling camera drivers: Completely remove and reinstall drivers if updates don't resolve issues ^[7]
• Testing with a different camera: If available, try a different webcam to determine if the problem is hardware-specific ^[8]
• Checking firewall settings: Ensure your firewall isn't blocking Slack's video streams ^[1]
• Making a test call: Arrange a test call with a colleague to verify if issues persist in a controlled environment ^[7]

For persistent video problems that resist all troubleshooting, Slack's support team can analyze diagnostic logs collected through the Help > Troubleshooting > Collect Net Logs option in the desktop app ^[1].