Describe what you can actually see
Record whether there is a picture at all, whether it is stable, whether on-screen information appears, and whether the issue happens consistently. Note whether a recording contains the same issue as the display, if your equipment supports that comparison.
Avoid changing channel settings, firmware, antennas, and display options in one burst. You want the next observation to tell you something about a specific part of the system.
Confirm the exact equipment path
Identify the camera, video transmitter, receiving hardware, and goggles or display. Verify that their models and versions are supported together. In a digital system, a shared ecosystem name may still require checking the exact compatibility list.
Follow documented power, antenna, and cooling requirements. Some video equipment can become hot during stationary bench use. Do not extend a powered test simply because you have not found the answer yet.
Treat antennas and connections as real components
Inspect mounting, connectors, and visible damage. Verify antenna frequency range, connector type, and the polarization requirements of the system. A familiar-looking fitting does not establish that every part is appropriate.
If a fault began after a crash or maintenance, inspect what was disturbed before experimenting with software. A connection that works intermittently can make almost any setting look temporarily successful.
Separate the picture from its overlay
Missing OSD information can involve the configuration or communication used to generate that information, even when the underlying video picture is working. Follow the applicable documentation for the flight controller and video hardware rather than treating the overlay and camera feed as one fault.
If the problem remains, report the exact hardware, versions, observed symptom, conditions, and checks already performed. Do not turn an uncertain video link into an excuse to continue a real flight.
MAKE IT USEFUL
Your next small job.
Classify the symptom as no picture, degraded picture, missing overlay, or recording/display difference. Then follow only the relevant chain.
Go straight to the source.
These official resources support the next step. Hardware, firmware, and local requirements can differ.