Check that the source equipment works correctly, for example:

- All video cables are installed correctly at both ends and not damaged (e.g. cable breaks or bent connections)

- Make sure that the resolution of the input signal is normal

- Resolution of the e-screen is set (1920x1080 @ 60Hz, 3840x2160 @ 30Hz for UHD e-screens).

If possible, test with other sources or cables.