Hi,
No video on controller seems serious. No errors about radio interference? All other remote functions work ok?
What I would do:
1. Record some video clip or photo and then read it from SD card inserted into PC. Black/scrambled picture would indicate camera issue - call support. If picture on SD card is fine then the problem would be in video link or in controller.
2. Check radio link/channel settings
3. Upgrade firmware
If it still doesn't help - call support.