nest cam outdoor just shows a black screen in the app, but i can hear sound and it's online

Diagnosis

The presence of audio combined with a black screen indicates that the camera is successfully capturing data and maintaining a network handshake with Google's servers, but the video stream is failing to decode on your client device. This is typically a "handshake" failure between the H.264/H.265 video codec and the Google Home app's playback engine. Because the audio stream uses a different compression method and a lower bitrate, it often bypasses the bottleneck that is blocking the video. This issue is frequently caused by a corrupted cache within the Google Home app or a temporary glitch in the WebRTC (Web Real-Time Communication) protocol used for live streaming. In some cases, it can be triggered by a "stuck" image sensor on the camera hardware that hasn't properly initialized after a power flicker, leaving the camera in a state where it transmits a null video signal while the microphone remains active. You can confirm this is a software/playback issue if the camera successfully records "Events" to the cloud (which you can view later) even while the live stream remains black.

How to Fix It

Follow these steps in precise order to reset the stream pipeline and clear the playback cache:

1. Force quit the Google Home app. On iOS, swipe up from the bottom and flick the app away; on Android, go to Settings > Apps > Google Home > Force Stop.
2. Clear the App Cache. For Android users, go to Settings > Apps > Google Home > Storage > Clear Cache. (iOS users must uninstall and reinstall the app to clear the cache).
3. Perform a "Soft Reboot" of the camera. Do not press the reset button yet. Instead, locate the power adapter for the Nest Cam Outdoor Wired and unplug it from the wall outlet. Wait exactly 60 seconds to allow the internal capacitors to discharge fully.
4. Plug the power adapter back in and wait 3-5 minutes for the camera to fully boot and re-establish its handshake with the Google cloud.
5. Open the Google Home app and attempt to view the live feed again. If the screen is still black, toggle your phone's connection from Wi-Fi to Cellular data to determine if a local network firewall is blocking the video ports.

If That Didn't Work

• Perform a Factory Reset. Locate the reset button on the back or bottom of the camera. Press and hold it for 10-15 seconds until the status light pulses. You will need to remove the device from the Google Home app and set it up as a new device. This clears any corrupted firmware flags that might be preventing the sensor from activating.
• Check for Power Undervoltage. If you are using a long extension cable or a third-party power adapter, the camera may have enough power to run the logic board and microphone, but not enough to power the image sensor. Ensure you are using the original Google Nest power cable and adapter. If using a POE adapter, ensure it provides at least 5V/2A.
• Disable Hardware Acceleration. If viewing via a web browser on a PC, go to your browser settings and disable "Hardware Acceleration." Some GPU drivers conflict with the Nest video stream, causing the black screen while audio persists.
• Update the Firmware. Check the device settings in the app. While updates are usually automatic, a pending update can sometimes cause stream instability. If the app shows a "Update Available" notification, trigger it immediately.

Heads Up

• Avoid using third-party power bricks; the Nest Cam Outdoor Wired is sensitive to voltage drops, which can lead to intermittent video loss while the "online" status remains green.
• If you have a high-density Wi-Fi environment, the audio (small packets) may get through while the video (large packets) suffers from packet loss. Consider moving your router closer or installing a Google Nest Wifi point within 20 feet of the camera.
• Regularly clear your mobile device's system cache, as the Google Home app relies heavily on temporary storage to buffer high-definition video streams.
• Check for physical obstructions or spider webs over the lens; while this won't cause a "black" screen in the digital sense, a completely obscured lens can sometimes be misinterpreted by the app's auto-exposure as a total lack of signal.