Quick answer
A black screen with sound usually means the device can't decode that video format — commonly 4K/HEVC or HDR on older hardware. Switch the player's decoder or choose the channel's FHD/HD version.
What you might see
- Sound but no picture
- Black screen on 4K channels only
- Picture appears after several seconds
Likely causes
- Device doesn't support HEVC/4K/HDR
- Decoder setting incompatible
- HDMI/HDCP handshake issue
Step-by-step fixes
- Switch decoder. Change between hardware and software decoding in the player.
- Use the HD/FHD version. Choose a lower-resolution version of the channel if your device isn't 4K-capable.
- Re-seat HDMI. Unplug and reconnect the HDMI cable; try another HDMI port.
Check it worked
Play a known HD channel; if it shows a picture, the issue is format support.
Still not fixed?
Tell support the channel, your device model and whether HD versions work.