Start with a clean baseline
Separate enumeration, permission, actual video frames, active resolution/frame rate and source/capture format. 'Detected' is not the same as 'working correctly.'
Live evidence
Relevant checks
Webcam TestOpen your webcam locally to verify that the browser can access and display a live camera stream.
→Webcam Resolution TestCheck the active video track resolution your browser receives from the camera.
→Webcam FPS TestEstimate the actual delivered webcam frame rate.
→Camera Focus Test ChartDisplay a high-contrast focus target and fine-line reference for visually checking camera focus behavior.
→First sequence
Do the high-signal checks before risky changes
- 1
Run Webcam Test outside the presentation app
- 2
Select the correct camera if multiple are present
- 3
Then check the classroom or presentation app's camera selection
Decision points
What the result should change
If live preview worksPrioritize the affected meeting/streaming app, selected source, virtual camera or profile.
If video works only at a lower modePrioritize cable/USB bandwidth, hub/dock topology or unsupported source mode.
If no frames arrive anywhereSimplify to direct connection, OS recognition and official firmware/driver guidance.
Browser can help check
- Open browser-visible UVC video
- Report active settings
- Provide focus reference targets
Browser cannot prove
- Control every document-camera zoom or light feature
- Inspect autofocus mechanics
- Repair firmware
Repair boundary
Know when to stop browser troubleshooting
- A browser cannot diagnose image-sensor electronics or lens alignment.
- Capture cards can be limited by HDMI format/HDCP/EDID even when USB enumeration succeeds.
- Do not install unsigned camera/capture drivers from download aggregators.
Used-device inspection
What to verify before paying or signing off a repair
- Verify the exact resolution/FPS modes you need
- Test microphone if integrated
- For capture devices, verify passthrough and capture are separate specifications