I'm using intex TV tuner(internal) card. the channels when viewing are only 75% & remaining is black.?

Question

But when we record, then full screen appears automatically and records full.

Answer 1

Try the cable direct to the tv.  I suspect it's the internal card, they are notorius for cable co. compatibility issues.

Though, it could be the tv set up.  Go into the menu and see if you can find something.

If all else fails, watch the programs through your recording device since it seems to decode properly.