There are only two possibilities, Hardware problem
or hardware settings ( Tuner )
It could also be from associated components on the
Circuits as well.
One has to check on it.
But it would be safer and cheaper
( repair of these kind is not cheap )
If you have a Set Top Box , then you can use the
Audio Video Out connect it on your Toshiba
DVD/VCR Combo Audio Video In
To watch or record the programs or channels
you wanted to see or view.
like these sample connector:
Use the corresponding Remote to change
programs.