Signal integrity / Troubleshooting guide
HDCP in Live Video Systems
HDCP is copy protection for compatible digital-video connections. When protected content is present, the source authenticates the devices in the path before it sends the image. A cable can carry a perfectly valid signal and the screen can still remain black because authentication failed.
What HDCP changes in a system
Every relevant device—switcher, extender, processor, capture device and display—must support the required HDCP version and participate correctly. The path also has limits on how protected sessions and downstream devices are managed. A product labeled “4K” is not automatically compatible with every protected 4K source.
HDCP is separate from EDID. EDID describes display capabilities; HDCP authenticates protected content. Both travel through the same general connection workflow, so one can be mistaken for the other during troubleshooting.
Common symptoms
- The desktop appears, but a protected application or clip becomes black.
- One display works directly while the routed system fails.
- The image appears after a restart and disappears after switching.
- A capture input accepts unprotected material but not a protected source.
A lawful troubleshooting sequence
- Confirm whether the source is sending protected content.
- Check the supported HDCP version for every active device in the route.
- Reduce the system to a known source, one cable and one display.
- Add switchers, extenders and processors back one at a time.
- Observe device status indicators or management pages for authentication errors.
- Power devices in the manufacturer-recommended or previously tested order when a new handshake is required.
The solution is to design a compliant path or use content that the production is authorized to reproduce without protection. Bypassing copy protection is not a troubleshooting method.
Prepare before show day
Ask content owners whether protected consumer sources are part of the presentation. Test the exact account, application, output adapter, resolution and routing equipment. A substitute laptop or streaming device can change the authentication behavior even when the connector looks identical.